The pasting multiple paragraphs gave me issues at first too, so while I've already given Zran the solution via Steam I'll repeat it here in case anyone else has the same issue.
Basically the sheet tried to notice any punctuation you already have in something being copied, so any line breaks you have will automatically try to push anything below the break into the next cell down. Simple fix is to take out any line breaks and paste it all as one block, then use Control+Enter to put the breaks back in and keep all the text in the same cell.
The second issue is even more straight forward, just look for the top, middle and bottom align buttons along the toolbar, should be right next to the more traditional left,right, centre align buttons.