Boot Manager & 2nd Init ROMs (need some clarification)

[Nadious]

Just got my hands on the Boot Manager app the other day. Absolutely LOVE the idea of what this thing can do. However, in trying to get it setup, I'm getting the warning message that I have to be on an 2nd Init Rom for this thing to be my 'phone rom.' I've done a few days of looking around and searching on the internet and I've got an understanding of what 2nd Inti ROMs are, but still not 100% sure if I can do what I'm looking to do with this thing. I recently got off of stock .605, because I lost root in my upgrade. (The on-click root method wouldn't work, so I ended up just SBF'n and starting all over.) However, in the process, I switched to Apex RC4 and I LOVE IT.

I'd like to try out some other ROMs and this Boot Manager app seemed that it would allow me to do what I want to do, which would be switching ROMs rather easily. But, here are the questions I have:

1. In order to USE Boot Manager, I need to be on a 2nd Init ROM. So, I'm guessing I'm gonna have to get OFF of Apex and use something like CM7 in order to get it to install properly?

2. Since Apex RC4 isn't an 2nd Init ROM, can I actually run it after I get Boot Manager working properly?'

3. If I can actually do that, then is there a way I can back up my currently Apex ROMs and restore it as one of the 5 slots in Boot Manager?

The whole '2nd Init' thing is brand new to me, although, it looks like it has been around for awhile, at least, based on discussions that I have read. I'd love to be able to try out ROMs a lot easier, but I'm really in love with the Apex 4RC build that I have and would like to use that as the ROM that I use the most. So, that's where I'm a little confused with all of this.