i) they can see the whole order book, whoever said they can't is not telling you the truth.
ii) it is illegal in Canada to lend shares that are posted for sale.
iii) correct, shares in a registered account aren't eligible to be lent, so it's only in a margin or non-registered cash account that you need to be concerned with.
iv) rules in the US or other foreign markets may be different, but they don't particulary matter. PTK trades on TSXV, so it boils down to abide by Canadian law or GTFO.
;-)
cheeers,
R.