You ask a lot of good questions, unfortunately many do not have a simple answer. I do not see what printer you have so any suggestions here are generalizations.

PLA prints within a range of temps but each style of printer varies with the hot end and thermostor/thermocouple type. I have a Printrbot that prints PLA fine all day at 185-190 degrees. The same PLA needs to print at 210 in my Prusa i3 Mendel. I am guessing that the temperatures at the nozzle are relative. You will have to learn what your printer likes? If you have an open extruder type, you may be abe to get a ball park figure by heating up the extruder and turning the feed wheel to see if it flows easily?

Again, speed is dependent on machine. My Prusa has to print much slower than my Kossel Delta printer due mainly to design and print head weight. On a perimeter print like a vase, I can ramp up the Kossel to 300 percent of normal and get good prints.

I typically print PLA on Blue Painters Tape with a heated bed temp of 40 or 45. I print on Kapton Tape for my ABS machines at 100 degrees. My son prints right on the glass with glue stick. However, we were given some BuildTak at last weeks Maker Faire and on our Printrbot and Untimaker 2, it seems to print fine with nothing but the BuildTak? We only have 30 hours printing on it but so far, it works great! I plan to try it on my Prusa and Kossel soon. The CUBE 3 uses a special plate glue that comes with the machine. I do not know what it is but I experimented with blue tape, blue tape cleaned with alcohol and glue stick and none of them worked.

Good luck and enjoy your printer.