The plane will not do 70-80 mph unless you are hitting no less than 14,000-15,000 RPM on perhaps an 11x6 pitch prop. I think you will only do 65 mph (as your engine with the stock muffler is not going to turn more than 13,500 RPM) and that is fast enough. I am sure the MDS 48 will be able to give you good vertical. The plane flies very well and can come in easy on landings. Flare her and she will be great.

To 3D with this place is not what I would advise ... the plane is not that light for 3D and neither are the control surfaces that big.