Hey, thank you for taking your time for write your thoughts down 
- Please contact our support for your 1. Issue:
support@shinyboxgames.com - We are going to balance it in 2.1 for sure.
- If you see any cheater, please report them here: [Reports Only] Report Cheaters & Hackers
Or you could write me a PM about it too. We are going to remove them from the leaderboard soon. Cheater are on a seperate league, so you will never face them unless, you got banned too
- Since DQ is an offline RPG. There will be always some hacker exist. With the item checker, we have already removed the bigger game breaking items. We are working on a better cheater prevention in further patches.