Which types of 360 hax allow XBL?
 

^ and which types of hax allow installation of XBLA content like how ps3 installs Duplex PSN titles

You can flash the DVD drive and play backups online no problems and also via xKey, Wasabi for playing games off a external HDD but for playing XBLA and many other things with zero problems then that's via JTAGs/RGH consoles but with that hack you can't go on XBL.

Basically you can do most things and still go online but certain things are longer to do as opposed to a JTAG/RGH console that is a smoother, easier exerience but unfortunetly doesn't allow XBL connectivity at all.

So JTAG/RGH is like a ps3 CFW, and x360/ wasabi allows backups from external like multiman and have a "OFW" mode, and flashing DVD drive is just allowing back ups from disc only allowing XBL from genuine disc

Yeah pretty much...JTAGs/RGHs are awesome and allow you to EVERYTHING but go on Live, the other hacking methods allow most things but also Live access so it depends what you really want it for.

I personally have a JTAG, flashed console and an untouched stock Slim for online...but not everyone is as weird as me :laugh:

You can't go wrong with either but from my experience, I couldn't be without my JTAG as opposed to the others.

Can JTAG work with games from HDD? Or you have to burn them to discs?

From hardrive
The only difference between jtag(rgh) and xkey or wasabi
Is xkey and wasabi have a pass thru mode to play online with original
But as for jtag you cant unless you get a dualnand setup
And jtag you can virtualey play everything from any region games
To dlc,s all from hardrive and a hole lot of emulators like n64 psx and hole lot more
Thats my next step after my beloved wasabi

You can do both if you have your drive flashed on a JTAG/RGH but if not you can just directly copy a game to your HDD. JTAGs/RGHs also allow playing games off of both a modded internal and an external HDD.

With regards to all these being applicable with XBL, @stussy1 has you covered.