My optimal goal is completing every quest. If anyone can provide a list of the minimum levels for every quest and i could work on those, i'd be very grateful. It's true that Santa hats right now are more than 70 mil (but dropped a few when I last checked) So you've got an impressively valued bank. I can sum up summoning effectively for you, I'm guessing.
The ability to summon is that allows you to create a familiar (acts as a cat would and follows you around) for a limited time. Each familiar has a feature. Some fight, some assist you in healing, others hold stuff to give you additional inventory space, etc. To give a familiar face it is necessary to have a pouch. The pouch is basically calling what you are used to (for only a short period of time, as explained above).
To make a pouch, you need charms. Making pouches is where the most of the experience comes in summoning. Charms can be obtained from monsters (slaying is one of the most effective methods to acquire charms). You'll also need blank pouches or shards as an additional ingredient. The pouches and shards can be bought from the man whom you began Wolf Whistle with in Taverly. To determine the second ingredient you'll need, read the summoning guides and check out the pouch you're creating.
Making the pouches are kind of like the herblore genre, but you must do it at an obelisk , rather than at any booth at a bank you desire. You'll need the supplies, and you make them. Hoping that the summoning was averted for you.
In a team, you'll have to have 100+ combat which is 75+ in Attack, and 80+ on Strength at a minimum with a 75 or greater defense to ensure you're not at a table eating all day. Take 70 prayers and piety, 43 prayer won't cut it. Take 52 summoning for a Terrorbird at the very minimum, and if not 67, then 68 for a War tortoise or Bunyip. Increase your magic (to perhaps 70) to be able to get there, and to protect yourself from being Mage-raped.
I say minimum for team are 80 attacks, 75 defense, 75 str, 52 summon,60 pray 75 magic for magic def. These aren't minimum stats. The minimum is 85/85/85 with 70 praying as well as 80 magical and possibly a fruitbat. After I put the stats that you suggested in zybez's fight skill calculator, the result ended up being 96cb. It's the minimum requirement and most teams will want for the 115 for chaotics.