You don't need a fancy chain tool, but a quality one helps. The chain tool on my Crank Bros multitool is darn near impossible to use properly. I've broken TWO cheap Spin Doctor chain tools, and now own a very nice Pedros, but my Park Mini has been the best value - small enough to be portable, but large enough to be able to actually put a little torque on. It is also very reasonably priced. I've had mine for 10 years now. I use the Park Mini whenever I'm not in my main shop where the Pedros is.

As to replacing pins... If I were a professional working with customers, I would always use the approved reconnector pin, or the approved master link (never reusing them), but for my own bikes, I don't mind repressing a standard pin, as long as it doesn't damage the chain. I've never had a chain break due to a repressed pin. KMC chains for 7 and 8sp are pretty thick and heavy duty, and I think there is plenty of meat there to retain the pin properly. The only time I get nervous is the super-light weight narrow chains for 10sp, and some 9sp. Repairability is one advantage that cheaper heavier chains do have. So anyway - I think it is fine to reconnect a pin, as long as you get a good seat on it, and verify that you have even penetration on both sides of the link, and properly loosen the tight link after pressing. It is worth knowing that it may not be an approved method by the chain company lawyers, and keep that in mind if you are working on a customer's bike.

-Sam