I have both and they are nice. I personally prefer the VX5 by a hair over the V4. I like the simpler reticle (windplex) for hunting plus it's a bit more compact (turret height).
Here is my opinion:
I'd get a decent power rack, barbell, weights, and a bench. Strength training should be the foundation to everything else. Walking or walking with some weight can then be used to improve conditioning and improve insulin sensitivity. There are various beginner programs but I...
I'd load up 76.8 and test seating depth. Looks like a pretty stable powder charge between 76.5 and 77. I'd start at -.020 off and work back in 0.005 increments.
A borescope will tell you for sure. However, you can simply clean the throat without a borescope and see if it helps with pressure. If you have an old cleaning rod that you can cut and attach to a hand drill, it will work better. Get a .30 cal nylon brush and wrap a cleaning patch around it...
Questions:
1. You swap between a Tikka compact stock and a regular size stock? Did you bed either?
2. I like the idea of a .223 but would be hesitant to use on say a cow elk hunt.
3. The SWFA is a fixed 6 power?
I don't own one but I'd look at an X bolt. If you want to spend a bit more or catch one on sale, Fierce makes a nice rifle. I'd go with some version of a 6.5 or 7mm depending on availability, reloading, and recoil tolerance.