Blade pulling out of the frame-There should be a spring that holds the quick attach latch assemble in lock mode. I found infomation on the Cub Cadet parts look up:
http://cubcadetparts.arinet.com/scri...rtISAPI.dll?MF
Click on frame to see a picture of the frame.
Slow reverse and slow lift- When was the filter on the hydro trans last change? Did you use a Cub Cadet filter and oil if it was change? I would change filter and oil first if it wasn't done.
If that doesn't help I would check shifter linkage. It may need some adjustment done to it. You will need a service manual to do that. I'm not sure where you can find one.
Let me know if this doesn't solve your problem.