Lil'Jeshua, you have a lot of ideas to test and IMO you aren't likely to be successful if you try testing too many things at once. What I would do is test one idea at a time so you can see what does what, if anything. Then spend some time monitoring and recording each idea using signal reports with some of your local contacts. IMO a one contact report is not very conclusive.
I've personally tried turning my GP upside down on my A99, and it took me about 30 minutes to figure out...that idea was no-way-no, and I think my models posted below might reveal that.
I've tried many ideas that I've read and heard were super successful in getting the A99 to show improvement by as much as 2 Sunits in some reports, but to be honest I've never seen anything that I've ever tried that made a difference I could tell just using my radio.
I've added my GPK with 72" and 102" radials before, I've made bandwidth curve reports using a feed line with and without the GPK included, but the only thing I ever noticed was the GPK tended to make the BW curve show a slight bit more curve...it was more bowl shaped rather than flat...compared to the A99 without a GPK. Otherwise I could tell no difference in performance.
However there is something else to consider. My station is on very flat land for many square miles around me out to 70-100 miles in most directions, so your results may vary if you live in hilly country. Even so...I still can't see much change in using any of the ideas that you have presented here.
You might do a search here on WWDX for Spider Plane and check out a thread where Bob85 talks about a special radial design he did using a Silver Rod EFHW that showed remarkable results. I modeled it, and if I can find it I'll post what Eznec predicted for that idea.
Based on the models I post below, it looks like your best results will come by using slanted down radials.
I'm just curious, does your GPK hub provide for both horizontal and slanted down radials to be installed?
I also added a recap from my notes of the results from these models at 32' feet high, with 72" and 102" radials setup horizontal, slanted up, and slanted down.
View attachment A99 with various radial setups 1.pdf