Let me try and answer your questions:
1: depends. If you have a decent supply of mythstones and know the recipes from the wiki, go ahead and craft thing but I would do that once your level 99+ and this provided that you have enough of a certain mythstone to look out for. Hope this helps. Mythics are very powerful items indeed for this game and a massive game changer.
2. Hmm. That again depends on the build. Not too sure how I could answer this question but if you have some knowledge of the affixes, maybe jewelry such as amulet/rings. If you look for ultra rare legends/crystal affixes found on items, craft easy items and items you will wear all time first. 2+ all sets on both ring and amulet is a good starter in crafting. Also a good idea is to have head mythic with the ring to be a resource mythic (mythic that can be placed on any piece of equipment) and an amulet with a sanctuary mythic usually. Again, I am not the best at giving tips but I will try my best.
3. For now in the vendor, only focus on common items that are bought for prices less than 8k gold if you can afford it and once gold becomes of easy supply, I think buy common items and crystals/mythstones. As for the 5M gold crystal, don’t buy it until you find that gold is so easy for you. Anyways converting legends/eternals is a better use of your gold for rarer crystal than vendor and for a cheaper price. Convert legends/eternal legends later on in-game if you find gold to be easier.
4. The → means convert to that crystal and rubik is pointing out that calcite can be converted all the way to quartz then ← meaning salvage all the way back to calcite and so on. The x just means don’t touch when crafting but as of this update, there are some exceptions to this rule because players finding gold so much easier and crystals so much easier as well.
5. Yes go ahead, convert eternals. Don’t convert eternal pets though or sell eternal maps and don’t sell eternals you feel might do quite good for you in later game. Its worth converting eternals that won’t be needed because of a high chance to get an ultra rare crystal (from jasper-obsidian crystal) and most of the time worth it.
Those ultra rare crystals are extremely useful in crafting because they can change item class,add sockets for potential mythics, remove mythstone from socket if need be, add legend affix, add set affix and the ability to add crystal affix. Very powerful and a huge step up in crafting. You can learn so much from these wonderful crystals.
They can be a big pain too if you don’t get what you want but it’s cool if you get them so well.
6. After your level99, you MUST ascend when you have enough gold and an exp farming gear for level1-50 exp farming with 6 quest mythstone for 200% exp gain. The exp farming is best done where hirling is the main dps dealer while you run around to get lot of exp. You must also have a fairly simple solo dps build for lvl50-99 for exp farming with 6 quest stones for 200% exp gain. A good example of this is XP farm build with the dankest of wizards [blightedswamp build] [pve] [wizard/warrior/rogue mythic 3 experience farming build]
Of course you don’t have to copy the build but you can get some idea of how you can level up from 50-99 fairly quickly and how to build the right build for it. This is best when you have enough resources so at first farm at a floor you are comfortable at (provided you built a basic farm build with maxed farm affixes such as gold find maybe, luck and item drops from a fortune mythstone or ruby.
When you know that you can level up from 1-50 easily and comfortably farm exp from 50-99, ASCEND!
A really good ascension would be either fortunate first for extra gold find and luck or dealer if you constantly get your inventory full quickly even if you have virtually just a bag or two of legends. It is all up to you and careful research. I did have to learn the hard way sometimes when I ascended but that is part of life.
As for your stashes filling up with legends, convert for crystals (if you have alot of gold) or sell most of them for gold (even better with dealer).
Good legends to keep though are legends that are not so common. They are rare legends such as mutiny gauntlet and insolance (rare because of defiant and ed%), nadroji robe and amulet for future farming because that nadroji bonus is amazing and some items that you WILL use for crafting right now/ sometime this month. Best things to keep in stashes are either crystals with items that are precious or have crystals take up half your inventory with mythstones and some precious legends in stashes. Either way works but I find that it’s quite effective to have crystals/mythstones in a stash sometimes as well as some /rare legends.
Look up on codex for certain legends that you need. The deemed “rare legends” are the legends with the description: found from powerful enemies then a floor number beside it. That means found from magic and above enemies. I believe it also says this on nadroji amulet/ring as well as vaccus scipio legend and maelstrom slicer. In previous patches, rare legends had the description: location unknown.
I do suggest that you build a decent basic farming build before you ascend which means farm floor 350 mythic 3+ for crystalline/mythical/eternalized set affix items if you want but you don’t have to if you can’t yet do it. This is just bonus for farming but the easy bit for farming is simply maxed 650% gold/luck and maxed 200% (300% item drops if you have hirling because of 100% bonus) item drops.
The crystalline, mythical and eternalized are bonus but help for finding eternals, crystal legends and higher rarity of crystals and mythstones. It does go good with the tier rarity that increase per 100th floor. that means from floor 100, calcite will never drop but angelite becomes the most common drop and this increase stops at floor 500 where common drop becomes kyanite. You will find this is good as long as you have decent dps build and farking gear.
I know all this sounds complex but just do the basics as in complete the journey to level 100, make a high enough dps build to surpass floor 200+ and have at least maxed 200% item drops from fortune, 650% gold find and 650% luck from epic affixes. This gets more complicated when you have hirling but you can look up on forums to know or trial and error to find out.
Believe me, I was once in that mess finding everything complicated but it gets easier after each step.
Back in my day when I played dq, crystal was hard. Really hard. Same with mythstone. Progress was quite slow in dq at the time until 2.0 came out. Still, it was quite slow but not as slow. Now that 2.1 has came out, everything is so much easier. What didn’t help is that I didn’t have hirlings to aid me but luckily at some point in this forums, I got hirling from @Teacup generously. They are massive help for sure. The reason why I didn’t get them myself is because I couldn’t pay for them or get my parents to pay for them. Hirling are a huge help in farming, dps, exp farming and getting to know the classes very well which is useful. Not only did I get hirling bur I got the luxury which is the premium stash, crystal/mythstone stash as well as the permanent map add-on so I don’t have to pay gold to reveal the entire map all the time. I thank @Teacup for making my dq gaming experience so much better and being able to catch up with other players 