I did the same thing...it could never get a rolling boil without the lid on and it took almost forever to get to simmering temperature.... used a 10" bango burner to build my own unit. Drilled out the orifice to 1/8" and plug it into my BBQ natural gas outlet. Works great.
When I make stout I steep the dark grains in cool water then put it in the fridge for 24 hours. I add the results to the kettle for the last 10 minutes. Works great.
Last time i forgot and added it until after I cooled the wort, with no ill effect.
You can get it out with a cheap plastic bag. just stick the end into the opening, move the carboy around so the bung gets caught in the side of the bag and just yank. I have done this a few times and it is surprisingly easy.
I have a glass bottling carboy. I tried it for fermenting thinking I could run the wort out of the spigot to a keg. Even though it is about two inches from the bottom it still sucked in some trub due to the agitation caused by the flowing wort.
I am sticking to siphoning it out...
Here in Canada we have returnable twist top beer bottles the are reused by the manufacturers.
I can cap then fine with a stand capper and they seem to seal as well as pry off bottles