The log says "Failed to load Chrome Extension transport", does this mean that i cant use mytrezor with Firefox anymore?
The log always says that if you are on Firefox; we first try to use extension, and if we detect that it's not Chrome (or -ium), we stop trying, but we still log it. To your question
I just noticed that mytrezor.com stopped working for me (Firefox on Lubuntu 14.04) as i get the message "Transport loading failed".
You probably still use the old plug-in, and it's kind of unstable in general. Disable it (in Firefox settings) and go to mytrezor again, and then install the new bridge.
Also i never updated my firmeware as i was afraid to loose my BTC because of some error, was there any reported problem caused by updating the firmeware in Trezors lifetime?
Well, stuff can happen. It should not, but it can.
Generally, when you are upgrading firmware, you should have the seed somewhere. If you have the seed, the worse that can happen is that the Trezor will be wiped and you will need to do the recovery and you still have your coins. You
should upgrade firmware, since we add new features and bufgfixes into new versions.
If you don't have the seed,
that's a big problem in general - Trezors are not infallible - meaning they can be destroyed by water or by being thrown really hard, etc! So protect your seed (that sounds awkward).
