sometimes on this board we get a little acronym happy. SMASH is a "single malt and single hop". Basic two row and the hop of your choice, or if your like me Marris Otter and the hop of your choice. I'd stick with a simple hop schedule and keep the IBU's under 30.
This won't be the beer that you give all your friends and says I've come up with the greatest thing since the invention of beer, but it will allow you to taste anything that maybe impacting those things that are giving you problems.
when it's all said and done and you say This is a plain beer, no astringency, no tannins, etc. Then start with the modifications, but only make small adjustments. i.e. keep the recipe exactly the same and do some water modifications, or keep the water the same and change the grain bill. then keep working back to the beer that you want to make. when you go from on stage to the next and something makes you go yuck, you know what caused it.
step down to smaller batches if you don't want 5 gallons of beer that you may not enjoy.
WOODY: Hey, Mr. Peterson, there's a cold one waiting for you.
NORM: I know. If she calls, I'm not here.
Keg1: Edmund Fitzgerald Clone
Keg2: Innis and Gunn Clone
Bottled: Belgian Strong
Primary: Southern Pecan Ale