I have paddled a Tempest 170 Pro for about five years now. Also close in size, I am 6’, 215. About the only thing that bothered me in the beginning was entering and exiting. I found I would often scrape my shin on the front of the coaming getting out. Once in the boat, it is a comfortable controllable place to be. I have a long torso,which means I stick up out of the boat a ways, a disadvantage in kayaking. I sit up straight with the back band pulled down tightly against the seat. It is more of a butt band. That is unless I am goofing off in calm conditions and slide down into the cockpit with my neck on the back of the coaming. As an aside, as you are a sports person, you probably are aware of the benefits of play, and learning how your body responds in different situations.
So, moving the seat. I have done this to a rotomolded Tempest 170 and to a composite one. It can be done without having to drill any additional holes through the deck. I moved my seat back 1", though 2" is possible. I did not notice any difference in how the boat tracked afterward. I actually ran into Steve Scherrer, the designer of the Tempest, at NW Paddlefest, and he said go for it, no problems. A thought on surfing big waves. Me, I am only an advanced novice, but I watch others having to move their weight forward and back to trim the boat on approach and descent. Sitting a bit back might change slightly how you trim. I don’t see it as a big deal.
The first time I moved the seat it took two hours, the next time one hour. The first step is to remove the seat entirely from the boat. I have included a link to a video on this. Remove all four bolts, twist the seat and then out.
https://www.youtube.com/watch?v=IXnWvZiX4Z0
Getting at those lock nuts from below is the biggest challenge. You work with the boat on its side and try to think your fingers as tiny as you can make them. Here is another video of a special tool thats makes it way easier. It is cut off, closed end 10mm wrench. I added a bit of a romex wire curl with tape at the cut end to aid handing. Here is video on special tools.
https://www.youtube.com/watch?v=Wf94YmlYpWc&list=PLEWas3LNCM2aZMIGw84CLX3jQSubtQhRJ
When you have the seat out you see that it has basically a plastic yoke that attaches under the deck each side. I believe the hole are 2" apart on center. I chose to make new holes in the yoke 1" further back, easily done as this is fairly lightweight plastic. I have heard people successfully shifting the seat back 2" by only using one bolt through the deck. There is a difference between the seat in plastic and composite boats. The plastic boats have a bullhead behind the seat that is vertical, and the seat base can move back 2" no problem. However in the composite boats the bulkhead slants forward at the base to help limit water volume entering the cockpit in a bail out. Moving the seat back 1" requires no modification to the seat base skirt. Moving 2" will require some trimming of the skirt, also not a big deal. It can be done with a razor knife.
So with the special tool and a little patience it is easily accomplished, and you get faster the second time.