You can fix the first problem by doing this:
1) Start Firefox. It'll open into the small window. Drag the window to as large as you can get it *without* using maximise.
2) Close Firefox down.
It will now at least size to that when it starts. You can then try maximising it and seeing if it'll save, I never run a browser in full-screen so cannot be sure if it works, but I often find sites that resize Firefox and it pisses me off, but the above also fixes it.
The rest of the issues you describe (copy and paste failing, apostrophe bug) I experienced as well on my Mac, and it was annoying enough to uninstall FF completely and use Safari. It doesn't happen on my PC though, so something must have resolved it. I also only found it happened on certain sites (not all), usually when JavaScript was involved. phpbb forums were a bad culprit.
What Extensions do you have loaded?
"Bite my shiny metal ass" - Bender, Futurama
No pixels were harmed in the making of this post
"Don't ping my cheese with your bandwidth"