Bother, I forgot to come back and reply. Let's see now...
Yes, seli, not sewi, oops. Blankets.
The repeated "lon" after "tawa" is just a systemic error. I'll try not to do that again.
According to a quick google, the average resting breathing rate for adult humans is around 12-20 breaths per minute - the book says they wait "for a full minute". Once a second would seem rather quick - but it's just numbers, anyway.
There's actually no reference to Dumbledore's glasses here (for once!). It's "the twinkling light that shone from his eyes" - I went for "the starlight", but perhaps "suno sama mun lili" (light like stars) may be better. Also, the verb here is "seemed to have gone out" - probably should be "li pini suno".
Hagrid is talking "in a muffled voice", so your literal reading is pretty much what I was aiming for.
Vocatives before, yes; but Hagrid never does. I think it's a dialect thing; and a couple of weeks back we had a brief discussion that decided there's probably no grammatical issue with them being at the end. I may have been placing my "o" incorrectly for a while, though.
Hagrid "wiped his eyes on his sleeve". Presumably "li telo ala" can be "to dry", as "li telo" can be "to make wet"? The "inside of gloves" problem can perhaps be resolved as "kepeken len pi insa luka sama" - "using the clothing of his elbow"?
As it happens, no - Hagrid doesn't just "start" the bike - he "kicks the engine into life". One assumes it's a proper old-school bike with a foot-operated ignition.
Aiming for "in a little while". And Prof McGonagall's bodily function (eww) is "blew her nose".
Rather more issues than I'd like, but nothing too insurmountable I hope.