Frank,
Question #2,? The MAL has a 1/2" hole in the center, then about six or eight 5/16 or 3/8" holes around the edge.? You will need it as the mount sits inside and is fastened by screws from the side.
Question #3,? I would get 35 - 40 pounds of weight, 20lb, 10lb and a 5lb - 7lb. ? Put the 20 and 10 close to the top, use the smallest weight as the lowest on the bar to dial in the balance.? Best for tracking.? If imaging, and using a guide scope do not forget to add that weight too. Guide scope, rings mounting bracket..it all adds up.? OAG is best and no real weight.
My question to you is,? is the Stellarvue SVX130T going to be your largest, heaviest, longest focal length scope you will use??? Reason I ask,? did you consider a G11G??? About 10 pounds less capacity, 60 or 65 pound capacity, photographic.? G11G has spring loaded gears in both axis, the G11T only Dec. ?? The G11T does have a bigger RA gear and comes standard with what would be extra on the G11G.? I'm thinking, availability to split in half, Dec / RA, clutch knobs, knobs to adjust azimuth when polar aligning.
I bought a G11T 4 years ago, thinking I needed it for a big scope, well I got rid of that big scope and did not need the extra weight capacity. ? G11T is a great mount, still in service today in a portable setting. set up tear down every night. Kind of anyway, it is on wheels, so it is just roll out / roll in.
Another thing I'd like to add is the Losmandy power supply, 15vdc., ? Gemini 2 likes the extra 3 volts. Get the dedicated power supply.
I cannot answer question #1 or #4.
In the under $5000 budget,? Losmandy makes the best mount out there, total package.? Dependable, durable, repeatable, customer service and customer support.
Just my thoughts, views and experiences, ? Joe?