I was thinking about doing two things to my nexstar this summer.

1. Take the Dihedral out of the wings and
2. Convert it to a taildragger.

Any advice/ Tips for me?[8D]

I would strongly encourage you to do this. Did it to mine and I am extremely pleased with the outcome. Got rid of the awful wheel carriage and used a 40 size wheel bracket mounted slightly ahead of the leading edge of the wing. Put a caster wheel on the back, took the wing apart, took out the metal rod and bent it almost straight; put it back in the wing, and off we go. Plane handles great, can do loops, rolls, etc with great ease. I would recommend beefing up the rudder ( I added about one inch) and installing servos in the wing for each aileron. Other than that, it turns into a great flier. In fact, it turned out to be my most favorite plane, ( I have midwing and low wing planes which I really like but the Nexstar is my favorite).

I did it to mine and got rid of that big ugly nose wheel.
I also went with a small 1" castering tail wheen and smaller mains.
I removed all Dihedral.
I mounted my wheel struts even with the leading edge.
Flies like a champ.
Vegas/