SRT4,
There are a lot of good threads on using the PC, if you can find them. Unfortunately, the search engine doesn't index words that are fewer than three characters long, so searching for "PC" doesn't turn up anything. Try searching for "PC*" instead; the "*" acts as a wildcard. That will probably turn up waaaay more posts than you want to wade through, so you might want to limit your search to "Search titles only".
And, to answer your questions IMO, the PC is a huge improvement over doing the work by hand . . . I find I get better results, and arms that aren't as sore. As for safety, use common sense, and you'll be fine. One of the reasons the PC is so popular is because it is relatively safe for the weekend warrior to use.
Tort