Mark Watt,

I guess I am a little confused by what you are saying specifically? The rigidizer will shrink the wool slightly but 50% shrinkage sounds a little drastic. When you said you trimmed the wool, do you mean you took out 50% of the liner or not? The important thing to remember is that forging is dangerous. Yes that's true. The best way I have heard it described is "this is a controlled explosion, treat it accordingly". If you have added satanite and plan to put in bricks on the bottom of your forge for protection, that sounds like you are treating the forge correctly. That all being said if you are concerned about your changes to your forge then get a lengthened connection cord to your propane tank, and test your forge outside. Another warning I have heard is that if you plan to use your forge in an attached garage then you run the risk of burning your house down. These are only warnings, I have run a vevor forge for over two years now, and I haven't had an issue, but every time I use my forge I check my connections, smell for leaking gas, watch for hot spots of glow anywhere near my venturi ports, and I always always check tightness on my cable clamps. The short summary: You CAN do whatever you want, but do your best to be as safe as you can and be aware of risks. Another great insulator for protection of your garage around your forge stand is concrete board that you can pick up at Home depo.I put those sheets on the ceiling, and stand, and walls around my hot things in my garage. 

The next conversation is around the "Culture" of the craftsman in the learning area. Here is my number 1 rule for advice. Don't let one or two bad experiences curb your enthusiasm. So far I have had one of the best experiences of my life meeting people inside this culture. Almost all of the people I have met have been overwhelmingly kind beyond belief. Almost all of them are willing to share if you are earnestly willing to learn and give back. Even if you have had a couple folks not working with you I encourage you to keep going. Now keep in mind the culture of those you might approach in ruraral environment might be from the baby boomer generation where you had to prove yourself worthy of their investment in you. Trust me that isn't a bad thing, They may have just been burned by a pupil that they put a lot of energy into that didn't work out. This experience can be everything you want and desire it to be. YOU will be that driving force. Godspeed Sir, best of luck in your endeavor. 

Hey Moose, welcome to the madness.
I'm not sure which forge you bought, but it looks like this one. (two burners)

I think that will lose a lot of heat with those big doors being open. The inner chamber also looks quite large and will take a while to come up to heat. Both the Satanite and the wool will absorb heat until they can adequately reflect it back into the forge body.  It is probably OK to use with the compressed wool. Make sure you tune the burners properly and get the flame in a nice light blue cone.

I have never used the rigidizer on my ceramic fiber blankets in any forge I have used or made, except one many years ago, so I cannot explain why yours shrank so much. Probably the quality of the wool. The description on that link says you can use it without a rigidizer or refractory coating, but it is always a good idea to coat the ceramic fiber blanket with a refractory. That stuff is nasty when it gets airborne and you breathe it in.

If you are new to the art of forging steel, I suggest a few things:
1. Take one of the ABS basic bladesmithing courses when you have learned the basics of how to move hot steel. This will focus developing techniques specific to forging blades.
2. Get Mark Aspery's book The Skills of a Blacksmith Volume 1. This will teach you the fundamentals of moving hot steel.
3. Find the ABANA affiliate closest to you. There are a couple in Portland OR and a very active one in Seattle WA. ABS MS David Lisch is, or was, very active with the Seattle group. Attend one of their workshops, demonstrations, or open forge events. That should help you expand a network of smiths and open doors for learning.
4. Post additional questions and show us photos of your work and progress. Don't think you have to post finished knives. You can learn more by posting what you are doing at each step in the process.
5. Check out and subscribe to the ABS YouTube channel. Watch a bunch of the videos there and watch them again. Tons of real information there from ABS smiths, so you know it is reliable and not just some guys trying to become Insta-famous.

My contact information is on the ABS website if you ever want to chat. 

"tried to set up training classes with local forges up in the city but have been ghosted when I mentioned I was setting up my own forge. (Competition fears I suppose?)"

dont let this influence you.  The bladesmith community is the friendliest community out there. you may have just encountered the one or two guys, or maybe they were just super busy.  Hard to say.  I know that if anyone ever drops into my forge, the problem is trying to leave.  Michael Samdahl is the same (I know, I was there)

A bit more reading for you