Question about Brother P-Touch Cube Plus PT-P710BTH

Yes, you can, you can create text fields (including multi-line) in the software like in a simple layout programme, adjust fonts (and font sizes), drag in graphics, etc. For multi-line printing, it's worth using 24mm tape, as the print resolution is not as high as with a "normal" laser/inkjet printer (but it's fine for labels).
I have been using it for about 1 year and find it very useful and well made. The only annoying thing is that it cuts off about 2-3cm of empty space for nothing before each label, even if you print several identical labels. This increases the sales of print ribbons (which you can get much cheaper at amazon noname)... ;)

Yes, that works.

Yes, you can print multiple lines, depending on the bandwidth and font size.
With kind regards
M. Blesi