Just a regular guy with questions

I am just an average guy. I am not a self proclaimed audiophile or a technical wizard. In fact, I still get confused by OHM's law. I have some simple questions about my system that I have been trying to figure out. First let me describe my system.
Amp: Rogue Magnum 88
Pre amp: Rogue Magnum 99
Speakers: Proac Studio 250's
TT: Music Hall MMF7

I have been playing around with different technics,tubes,cables, you name it trying to best detail the sound quality to my taste. First let me say that this is very difficult with the Rogue amp. Everything is under the cover on this amp. I really think this is a great sounding amp but, what a poor design.
I have had a problem for a week or so that when I would turn the amp on you would hear an electrical surge of some type. A 2 second zzzzzz. Tonight I decided to open it up and see if I could pin point where it was coming from. I pulled it from the rack and powered it up. I could not get the amp to do it again. I tried several times by powering down and back up again. Nope, won't do it. I decided that while I had the cover off I would try something. I was reading a article in a mag the other day that was commenting on a speaker. I can't remember what speaker, but they were saying that the speaker was rated for 6 ohm but was actually closer to 4 ohm. So they recommended running your amp at 4 ohm. Well here is where the real pain of the Rogue comes in. In order to switch from 8 to 4 ohm, you need to remove the 8 ohm tap from the lug and install the 4 ohm tap to the lug. Then put this plastic boot over the 8 ohm tap and let it dangle inside the amp.
Well anyways, I tried this and the difference was pretty amazing. I found the amp set to 4 ohm to sound much better than set at 8 ohm. Can someone tell me if this is okay to run my amp in the 4 ohm mode while the Proacs are supposed rated at 8 ohm?
I also have a most likely stupid question about TT cables. I would like to switch out my stock cables from my MMF7. Are TT interconnects the same as other interconnects? Can I use any interconnect I want or does it have to be specificaly a TT lead? Thanks for any input.
the 2 second buzzing sound sounds to me like something is slightly loose inside the chassis, when you moved it and opened it up, it might have knocked whatever it was back in place..
It's no problem to run the 88 on the 4-ohm taps with 8-ohm speakers. I think you get a few less watts of power this way but also less distortion and a higher damping factor. It is the preferred way to go in many instances. Also, if you haven't already done so, you can switch the amp from its ultra-linear mode to the triode mode (with the cover removed and power off). When I had mine, I ran it with the cover off and I thought that made it sound sweeter and more dynamic. And the triode mode is more liquid and less edgy than ultralinear.

And as I recall, the Rogue 99 preamp is very sensitive to the chassis-to-shelf interface. If you want it to sound more detailed and more articulate in the bass, try it with #4 BDR cones.

As for the TT interconnets, yes, you can pretty much substitute whichever ones you think sound the best. They don't have to be turntable specific.

Happy Tweaking!
TT leads may not HAVE to be specific for phono, but with the very low level signals involved (esp. w/mc cart), using phono leads is recommended. Many tone arms come with a one piece lead from cart to RCA plugs, in part for this reason.