That poor transition going from low speed to high speed is simply a tuning issue. The low speed needle is likely too rich and needs to be leaned a bit. To test your low speed needle setting, start the engine and leave it running at idle while you pinch the fuel line going to the carburetor shut with your fingers:

A) If the engine runs and runs and runs then speeds up and quits, your low speed needle is too rich. Lean it 1/8 of a turn and retest.

B) If the engine quits almost instantly without picking up rpms first, your low speed needle is too lean. Richen it 1/8 of a turn and retest

C) If the engine picks up rpms a bit then quits after 2 to 4 seconds, your low speed needle is just about right.

As for the engine "pulsing" at wide open throttle and air bubbles appearing in the carburetor line:

1) Check your clunk and clunk line inside the tank, make sure the clunk line is free from splits and tears. Make sure the clunk hangs down toward the back of the tank so that there is still 1/8" or more of space and the clunk can't rest against the back of the tank. Feel free to replace your factory clunk with an O.S. Max bubbleless clunk.

2) Check the line from the tank to the carburetor and make sure that it is free from spits and tears. Replace any fuel line that seems less than soft and flexible. Use Du Bro fuel clamps on any fuel line connection that doesn't feel snug or that seems like it could easily pop off.

3) Check the remote needle valve/needle valve assembly and make sure that everything is tight and secure.

4) Check all of the fuel lines for proper length. The carburetor, remote needle valve, and exhaust lines should be long enough that they aren't tight or strained to reach their connections. They should also not be so slack that the fuel lines bough out or form u-bends before reaching their connections. Trim or replace any fuel lines that don't look "just right" with regard to length.

5) Go through all of the cylinder head and backplate bolts and check them for tightness. Make sure that all of these bolts are very, very snug. Check the carburetor and make sure it is mounted tightly to the crank case. Air leaks at any of these points will cause the engine to run lean and will make your engine almost impossible to tune.

6) Run your engine at full throttle and stand behind the prop looking carefully for leaking fuel. A little bit of extra fuel coming out of the exhaust port or muffler seams isn't any big deal. Fuel dripping from the seam between the cylinder head and the crank case or fuel spitting out the front of the crank shaft can be another story. Either of these conditions can indicate engine component failure and will result in the need for a new cylinder head gasket, new bearings, or the like.

7) Do your best to remove your fuel tank, pad the fuel tank with some protective foam where it will fit, and then put the tank back. It never hurts to try to isolate the fuel tank a bit from the vibration of the fuselage.

The Evolution TPS is a terrific engine. You've done the right thing by removing the flywheel. Try to get both the high speed needle and low speed needle limiters off so you can actually tune the engine. If you go through all of the above steps, you'll be rewarded with a nice reliable, powerful .455 twin needle dual ball bearing sport engine.

As for props, there isn't anything wrong with 3-blade props in general. The Evolution TPS prop, however, is a blunt-tipped 10.5 x 4 that is very inefficient by design and is usually balanced poorly. I'd recommend that you try an 11x5 two-blade prop for training, then an 11x6 two-blade or 10x7 three-blade when you're looking for some extra performance. The 10x7 two-blade prop you're using now is more of a speed prop with your engine and it will make the plane land a little fast for training.

Good luck with the troubleshooting and tuning!