for mysql , only the old mysql will work , newest mysql generate a lot of bugs and you going to have a lot of work to fix those tables (specialy the wrong value's )
this is because so mutch has beein changed betwean mysql 4 and mysql 5 ( or mariadb for that part )
you could try with other forks of mysql , but they mostly do the same
then for the failed to connect
1) edit ALL files , including HEX edit ( or notepad++ to keep NULL value's ) so the server can start up
2) use the RIGHT client, a wrong client also do not connect ... version mismatch stuff thingy code
if using on localhost , make sure the ports are avaible and that the server is bind on localhost and not on a internal ip adress ( 192.168.1.50 != 127.0.0.1
ip need to match in your client , 127.0.0.1 != localhost
and for the other debug , its hard with out knowing what exact you dit
Greets from PowerChaos