Hello! Been a creeper on the forums for awhile now, finally getting in on things.

Hey guys, I've been an owner of a 2011 1.4t Cruze with 79k miles and the LT2 package for the last few years and have always found myself running over here to find information on this and that about my vehicle. So, I figured I would join in after all these years haha.
*sorry had to edit out hyperlinks due to post count*

I've been through quite a bit of trial and error on how to get better mileage and performance out of the car as driving carelessly while in a hot humid Houston on regular produces some pretty disappointing results. I have thought about just giving up many times and trading the car in even though I really actually do like the car.

So I'm going to make one last big push to save my car out of trade in and have a list of things that I'm considering and was wondering what you guys think about them.

First is that I would be doing a seafoam cleaning, given there are a couple options here which would you all feel would be the most appropriate? The SF-16 motor treatment or the SS-14 cleaner?

Second is that I would be changing out the spark plugs for some of these that I saw stickied in the main forum, would be installed at the 0.028 gap. Going with the iridium because honestly, I'm lazy, and these seem to last longer between changes:
*NGK #2668 iridium plugs*

Third I have been using mid grade and premium grade gas as I truly run my AC constantly here in Houston and the performance and mileage suffers immensely if I run regular. I have wondered if there is an additive that might be an acceptable substitute for this though.
Given the cost per gallon difference on a tank of gas is there an additive that might make my engine run cleaner than a pump gas while having the anti-knock effect I need and come out to a cheaper price.
Now obviously this is the same as me asking for a miracle, can I slap an additive in normal gas to make it better than premium, but I figured it doesn't hurt to ask.

Fourth I am looking at the Trifecta tune, given I'm not looking to upgrade many things performance wise or looking for much customization their canned tune for $300 seems ideal:
*Trifecta turbo advantage*

I haven't spoken to them as of yet so I'm mostly going on what I have read here, that it can be set to the factory mode and would run exactly as before or sport mode for a little more get up and go.
I'm well aware there are other options but they cost 50% more and I'm not looking to really monkey with it too much it would be a tough sell to switch me over.

I have just been running which ever brand of full synthetic oil without much thought to it to be honest, it has always been changed at prompt intervals given the drastic effect I've seen with older oil. Are there any oil treatments that might be worth exploring? Have looked at some of the lucas oil ones but I'm not interested in slapping down random purchases on treatments that may only have a tiny benefit or worse none.

I appreciate you guys taking the time to read all this and any input on what could save the car from a trade in would be much appreciated. I really do like the car, I just cant justify the mileage and performance I'm getting out of the car.