My background is MSSQL as well, and imo, your bro should have no difficulty seeing how things currently work - but like me, freaking out that MySQL is so limited in what it can do comparitively. MySQL works for what we're doing, and it's free. Two great perks.
I'm sure many a DBA have reviewed this beast in the past, yet here it stays.
My interested would be in getting it faster, rather than worrying about orphaned data or ID ranges. But you'd be amazed how well MySQL runs on a dedicated FC4 box doing nothing but service MySQL to the Emu. Time to buy more hardware.