My god... Reading most of this is exactly like when someone running Windows has a simple problem and 100 people jump on board to explain 1000 things that will not solve the simple problem and actually create new problems.
1. If you bought a new speaker setup and it doesn't sound right and you cannot resolve it simply and your ears haven't changed, ditch it an get something else.
2. If you are thinking you have to add some new external hardware to your system to achieve something you already had previous, that is a fail.
3. If you get advice that is not simple and obvious, that is a fail.
4. Follow your ears. Accept less than perfection and make up the difference with your playing. Unless you want to do like we all did in the 80's and end up with $10k rack monsters that weigh 400lbs and have manuals with more pages of info than it takes to launch a rocket into orbit.
The ultimate goal of any setup is to turn it on, start playing, and enjoy what you hear. If you get too deep into gear nonsense, you are a tweeker not a player.
Bonus: If all else fails, buy a pro tube amp / speaker setup and enjoy. If that fails, quit guitar and play drums. If that doesn't work and you can't sing, sell all of your gear, move out to the country and become a farmer.