She needs your help! Please help diagnosis her!

This lady has been doing fine until 3 wks ago. I saw some mites on her and sprayed her down with a mix of spinosad and azamax. Did this for 5 days straight. Then added azamax to the water to treat systemically. Signs of those nasty mites are gone. However she is starting to yellow and lose leaves daily. Seemingly the bottom leaves for the most part, but there are some upper leaves being lost too (75% lower hanging leaves & 25% upper). I tested PH and its at 6.8. Soil is 707 from roots organics. It has been very hot outside 90f and is in full sun 75% of the day. She is still drinking water but not excessively. She needs a good haircut i know and i just bought a 100 gallon fiber pot and all new soil to give her a nice home. I am scared to transplant her right now given that she is showing stress signs. I looked for bugs and can't find any.
Nutrient lock is my guess or root bound, but roots are not showing out of the holes in the bottom of the pot??? If it is nutrient lock, can i pull her out of the 30 gallon pot she is in and rinse roots thoroughly and stick her in her new home?

I am very stumped to why this is happening. Any input or suggestions would be great!

Cheers,
Justin

You should not apply oil based products so aggressively on plants in direct sunlight. My guess is that is your problem. Even if you applied at night, it is just too much.

Re pot it i think its rootbound and if i were you i would put it straight in a hole in the ground, carefully.