You can't tune e85 to knock limit, that's way too far and you'll be down on power with that much advance. You really want to be doing e85 on a dyno to get it right. Stock head bolts don't have tolerance left in them either.
Really, I'd play with your wastegate duty cycle, I have no drama getting 16psi or more by 2800-2900rpm?We have now three cars, that are equipped with Adam's cams and it seems that they are a very good choice with standard td03 turbos. It's a whole different car and cams is a bit easier mod than bigger turbos. So I'd recommend these as an option. Stock turbos reach full boost in about 3500rpm as td0413t needs 500 rpm more.