Clean v15 (vs2019)

Hi Good Day!

I am new on Flyff Development.

I am using a clean v15 vs2019 files and I want to start fixing the hacks, exploits and other things to become stable and secured files.

However I only knows a little on exploits/hacks so I dont know where to start/begin to fix it.

-Character Delete Dupe
-Mail Box Penya Hack
-Guild Warehouse Dupe
-Angel Creation Dupe
-Pet Stat Hack

so far this is the only hack/exploits I know.

so im here for asking for a list of Hacks/exploits/Bugs that needs to be fix on a v15 files.

Thank you so much in advance.