Delaware Valley Tackle

Sounds reasonable. Put them together and see for yourself. Only you can tell. There's no right or wrong.

Good. I'd clean up the shaft with some 2000 grip paper, install the gearset and matching Carbontex drag.

5" off a tip that Rod won't be good for much of anything. Good news is that a qualified Rod builder can splice that. Contrary to some assertions, properly repaired and you'll be hard pressed to tell the difference.

Roll the spool on a table top and see if the shaft is off. That could cause the rub and gear noise. Maybe replace the pinion support bearing in the frame. These aren't common or likely problems just things to check.

Depending on the soil level simple green rinsed with warm water, mr clean magic eraser for cork, Pledge polish on the Rod and u40 cork sealer on grips.

Are you inserting them?

For sheer casting distance spinning tackle can't be beat. That's not a good comparison. The Rod has more to do with casting. A good deep cleaning will do a lot for a reel and the PQ is a good one.

MH etc are subjective terms. The rods versatility depends on the weights you want to cast and the Rod itself. Personally I prefer very different rods for the shallowest and deepest baits. For versatility a 7' moderate glass Rod with a lure range of 1/4-3/4 is what I'd look for.

X2 plus they come on 4.7:1 as well.

Across the board I like the E series. The I is a good reel but more different than better compared to the E

You have two different problems. They may or may not be related. Bad spool bearings screeching is actually pretty rare. The failure to immediately engage upon turning the handle is not unheard of in Daiwas. It's a fairly easy fix for a reel tech. It's not the gears slipping it's the ratchet against the kick lever. I don't have enough info to diagnose the casting noise. Our reel repair service is very reasonably priced at $22 and members here get 10% off that. Parts and shipping are extra . It's your call whether or not the reel is worth sending in.

Mastering different types of tackle opens options and enhances the overall angling experience IMO. It's not mandatory for successful fishing but I'd encourage you to .

The braid is slipping on the spool. Reel it onto another reel, add mono backing and top off with two full casts (75 yards or so) of braided main line.

A senko is not really all that light. Any good casting reel setup properly will handle that. The 50 size is about as good as you'll find without opening your wallet for one of the specialized BFS models.

OP, what do want to do with the Rod n reel combo?

There's no system. Each brand is a little different. The chart posted above is a good starting point but not 100% accurate across the board.

The only thing I'd disagree with is spinnerbait weight not mattering. Weight and blade choice both affect running depth. I prefer 3/4 spinners most of the time 1/2 in shallow or over weeds

You're on the right track, especially with the brakes. It's actually not all that common for bearings to get to the screeching point. The brake tabs may need replacing or cleaning. Swab the drum and tabs with denatured alcohol the oil the drum very lightly.

Keep in mind a reel is a mechanical device with several moving parts. It's not at all unusual for them to make some sound. Even the highest end reels may not be totally silent under all conditions. If you're really concerned exchange it.

Just remember, any nylon thread will darken and become translucent with finish.

True, a blank can be successfully repaired, but two inches at the tip doesn't leave enough to work with.

I don't think you want a "heavy" for what you're doing. There are lots of nice blanks to build on. Email me and I'll send you a detailed preliminary quote and kick it around.

Thre result of taking 2" off that tip will be a slightly slower action and an increase in the low end of the lure weight range. Good news is that neither change is catastrophic for a flipping Rod. Give it a try and see what you think.

How fast can you reel? My guess is you're spinning the handle hard and then stopping it. Am I close? If so, there's nothing wrong with the reel other than being misused.

"Force" no. Worth a try? IMO yes.