Stop worrying. You made a good choice for an engine. I don't know that the pump was needed, but it won't hurt anything. Just plan on putting that engine in there with a Pitts style muffler. I built a Top Flite Cessna 182 some years ago and it weighed in 12.5-13 lb. range. I powered it with an O.S. Surpass .91. In the years that I had it I never wished for more power. More than enough for scale like flight and then some. The TF had 100 more sq. inches than yours which possibly helped with the lift. However, a 1.20 Surpass would have been a lot more than necessary. I flew off thick grass.

Don't bother to install your nose gear. There are helpful suggestions in this thread. Get the best you can afford. Full size and model alike.....nosegear takes beating on a Cessna. Replacing it now will avoid a bad day at the flying field and possibly damage to your new bird. Bite the bullet and get a proper nose gear. And.......don't be caught flying this without a nice pilot sitting in the office. This isn't a drone!..........