Could Use Some Help With MAME4iOS, MAME4all, iPAD + iCADE

[Rotgut]

Hi, everyone. Just went Ultimate user... good to be here. Some info first. Using an iPAD 4th Gen, jailbroken and Cydia app as of last weekend. I have been an avid MAME fanatic for many years, built a MAME cab, etc so I am fairly competent with the way this works, how to get roms to run and so forth. I'm adding an iCADE soon. I also ordered new IL buttons from Ultimarc and a Sanwa ball top stick from Focus Attack, as I am doing a complete swap-out. I have been using iExplorer to drop roms into the iPad.

Having some aggravating issues. so a few questions for anyone who might be able to help me out:

1) Which version of MAME for iOS should I be using with the iPAD and iCADE — MAME4all or MAME4iOS...? Why are there two versions co-existing?
2) My understanding is that I should be grabbing MAME 0.37b5 version roms to run on the iPad, correct?
3) Why do some roms appear lit up in the list in a MAME app and others do not? They come from the same "version" of MAME so I don't see why they would not be all "good to go"...?
4) One rom will "light up" in the list and run on MAME4all — but not "light up" and run in MAME4iOS — why?
5) Other than roms, do I need to download and place other files such as CHD files, BIOS files etc? If so, where do those go?
6) When I download a multi-pack of roms do I just drop that zipped pack into the folder or do I need to unzip it to reveal all the individual zipped roms and then drop those into the folder?

I'm confused. Any help is very, very much appreciated. in advance!