New to trading - wish list: Is it possible to purchase games from others using wallet funds?

I don't think you can. People will ask for paypal, though. No idea how that works.

isthereanydeal.com : to check if the game has been bundled
steamdb.info : to check the lowest Steam Store price

To answer your question, it depends on the traders. You create a thread on Steamtrades and point what you're willing to trade for what. You might get offers or not. Most common is a game for a game trade.

Edit: Just to add, if you have zero reputations, most likely no one will want to trade with you, since your account is way too fresh and empty (9 games).

Almost no one takes wallet and definitely no one wants to take their time to look through others wishlists. The most efficient way is probably through CS GO keys on the market then trading them in for games if you really want to use funds.

Got you, do the keys usually resale quickly? I would rather not get stuck with one...