echonaut: You should make a new account for your purchases so your account does not get banned!
That's my plan if I continue this further than simply 3 gifts, and it's part of the reason I'm limiting it to 3 games at this point. I'll definitely be open to doing more gifts in the future if interest exists.

Why would your account be banned? Doesn't Steam like money?
Guessing something with selling gifts. Might be against the rules, I don't know.
How much is Portal 2 pre order? It's stand alone?
From
https://support.steampowered.com/kb_article.php?p_faqid=549 :
May I sell or trade gift subscriptions?
Steam Gift Purchases can not be sold or traded. Attempting to sell or trade a gift subscription is a violation of the Steam Subscriber Agreement and may result in your account being permanently disabled.
Also accounts can be banned if they received a gift that was payed for with a reversible payment method and has been reversed.