We got our first pool this year as well. The TF100 is a nice kit. It seperates your daily tests, from your weekly. The dailies are in a smaller kit, which is nice.
As far as leveling, although we had a store install our pool, we did help a friend install his. Ours just required too much excavation and 6-7 tons of surrounding stone.
When we installed our friend's pool, we used a Dewalt, cordless, laser level. These are expensive ($1,200+), but if you have access to one from a commercial drywaller it helps
Our installers used a 6 foot level on an 8 foot "leveler" piece. Do the math and you'll know that every inch past the 6 foot, the "leveler" becomes the "unleveler". All in all, our pool is only 1/8" off front to back. Side to side is perfect. The pool we installed with the laser level is just as good, but honestly was easier to level.
If you have clay in your soil, like we did, the installers used screening, which helps take some of the sponginess out of the ground. I'm not thrilled with our "professional" installation, so if yours isn't perfect don't think you made a mistake to DIY. At least with DIY, you can always say to yourself, "I don't install pools, I'm a fireman." Or whatever your occupation. Paying someone to mess up your install is worse than messing it up yourself...unless of course your walls cave in
