Would someone be so kind to briefly walk me thru the process of how to properly secure a fiberglassed roof?

Basically.. i'll take the headliner down.. build a wall in my car, then from the B pillar on forward, that will be fiberglassed, ok?

this is where i get lost....

How do i attach the fiberglass mold to the vehicle so i could remove it again if i needed to?

Go to FloridaSPL.com and check out there forum, a member by the name of CandeShop just got done fiberglassing his CRX roof.

http://www.floridaspl.com/forums/showthread.php?t=11006

so basically i'd remove my headliner, cover it in reynolds wrap.. lay down cloth and resin it a few times..

After that(i'm retaining the view thru my sunroof), i cut whatever i want to out of it for custom purposes for adding things up in there then just sand, paint(or wrap) and install it the same way the original was?

Here is where it get's tricky-

My headliner is held in via Velcro. Some locations like sunvisors and dome light, etc.. have screws ran through the stock headliner but the rest is held in with velcro.

I'm assuming a fiberglassed mold will be significantly heavier than the stock headliner... What else can I use besides velcro that will still allow me to remove the headliner because i do not think velcro is strong enough.

Some 3M double sided industrial tape, or some 3M industrial Velcro. Either of those stick. The Velcro would probably be the better choice because it allows you to pull it back down. The Double sided tape is expensive too, especially if you have to replace it every time you pull it down.