FLAC volume gain with foobar2000, FLAC volume normalization with foobar2000 Options

[oppo]

Hello Guys!

I'm new in this FLAC thing, and wanted to try out. I ripped my audio cds with dbpoweramp (absolutely uncompressed) and use replay gain with foobar.
Maybe i've done this gain thing wrong, or correctly, but I'm not sure if it's worked or not.
I use mp3gain for my mp3 files and it works like a charm. When I was testing I used the same player and the same song in mp3 and flac format (gained with mp3gain and foobar). I listened the beginning of the songs and the mp3 version was louder (and that's the volume what I want).

Is mp3gain ruins the quality or it uses the replay gain thing?
Is there any software like mp3gain for FLAC where I can tell the exact dB value what I want? (In mp3gain I use 96,2 dB)