With that Walbro 255 I would defintly get a AFPR. Your running richer that you need to be.
The downside to higher fuel pressure than needed at your stage is power loss and decreased gas mileage.

Too much fuel can cause the bad gas mileage & fouling the plugs a lot faster. Keep it adjusted to the mods you have

I just bought some evo 590cc injectors and was considering turning up the pressure to 4 bar for if I upgrade to the 68hta instead of the t-28. I am torn between the totally stock appearing t-28 or going with the fp68hta. I think that later I will be happier if I go with the 68hta but not if I grenade my engine, trans, and center diff on my daily driver.

Other downsides could include bad O2 sensors, first one of which is obviously important, and if it is rich enough I'm pretty sure you can wash out the rings.

I have dsm link and a wideband can't I tune it to not run too rich even if I raise the fuel pressure?

I highly recommend sticking to the DSMtuners horse power upgrade path. Its a logical path for upgrading your DSM so you wont be installing expensive parts that you can't even use yet, or worse... destoying your engine. I've used it... it works. It WILL save you future head aches.

I will have to check it out thanks

My fuel pressure is a little high (about 43 psi at idle with 13" vacuum) and I have all three of my LTFT's hanging around 0%+or-1.5%. It's been that way since '07 and I haven't found the downside. If anything it helps me stretch those FIC 650's just a little bit further.

If you try to stretch it too far you'll probably reach a point of diminished returns, and possibly risk exeeding the pressure capacity of your pump when you turn the boost to say, 35psi.