I have a model 110c left hand shooter in 30-06 which I bought about 28 yrs ago. Until last year everything was factory until I had the trigger lighten to 3 lbs. Being new to the forum about a month old now, I have learned that it is easy to exchange barrels on Savage rifles. My questions are as follows:

1. Does this apply to my rifle model as well?
2. I would like a 28" heavy barrel for varmint for 110 gr and a 1:12 twist is this the right twist?
3. I would like a 28" heavy barrel for long range shooting using 180 to 200gr, do I need a faster twist like
1:8 or will 1:10 stabilize the heavy bullets.
4. I would like to mount this on a PDC Stock, can all this be done with my old 110cl action?

Would truly appreciate your expertise in this matter. I do not want to buy any different calibers. I wanted all in 30-06.