Well the brightness doesnt really affect me as I will only use it at night to watch movies with a totally dark room.
As far as plugging it in I would use an HDMI to VGA cable which would take care of it not accepting component video I would think...
Size, I dont care im building a casing for it so you will not be able to see it (and yes it would be very well ventilated).
So... why else wouldnt I want a crt projector? (Oh and their bulbs last forever which is a HUUUUGE plus for me)... And potentially can project 1080p and 720p right?
You can't convert HDMI to VGA.
If you have sold yourself on the idea, then you need to take a SERIOUS step back and do some research.
Yes, CRT guns go bad.
CRTs also have tons of non-replacable parts inside. They have a ton of electronics inside which are 100% out of production or horrendously expensive to repair.
Retubing a CRT projector typically costs upwards of $5,000 (!!!)
Don't take lightly how much maintanance is required for CRT projectors, and that CRT projectors are basically out of production - there's a reason for that.
People went to specialty classes for a week to learn how to properly set up a CRT projector... how is it that you are convinced that you can just set it up? Keep in mind CRTs are nothing at ALL like DLP/LCD/LCoS projectors. They aren't digital.
Also, don't discount the lumens we are talking about here. You really need a positive gain screen and will be limited to about 92" with the low lumens which a 7" CRT puts out.
Don't get me wrong, I went CRT with my first projector... but that was about 8 years ago.
This is what I got to replace it with...
http://cgi.ebay.com/Panasonic-PT-L300U-LCD-HDTV-HD-Home-Theater-Projector_W0QQitemZ230303542576QQihZ013QQcategoryZ48654QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
It was SO much better and easier to use than the CRT it completely blew me away. Keeping in mind that it does not have a HDCP compliant DVI input. I still use it to this day and produces the results you see in these photos...
http://www.avintegrated.com/lighting.html
Now, consider that this will likely go for around a couple hundred bucks, and you have something way easier to set up than a CRT, brighter than a CRT, and more compatible with HD than your average CRT.
After I turned mine on for the first time, I had my CRT projector on eBay that evening.