Hi,
+2 seems correct.. +8 is the value that you use for dumping
You can combine the tracks using the command link: if you have all the .bin files named in the right order in a folder you can do 'copy /b *.bin game.bin' to create a single binary with all the tracks. You'd still need a proper .cue then though. I don't remember how this is done for single binary files, so I hope someone else can help you with that.
For games without audio tracks you can use a generic .cue.. for psx (which is mode2) you can use the following:
FILE "game.bin" BINARY
TRACK 01 MODE2/2352
INDEX 01 00:00:00
About converting previous one binary dumps: you could try mounting this dump with Daemon tools and then dump it again in EAC, but you'd have to know the correct offset values.. also, the .cue would have to contain the correct gaps.