It's highly beneficial to one's enjoyment of the game to see if you can get a group of friends going to play it regularly. Even if you don't have a bunch of people nearby who want to play, it's usually easy to find some more vocal players, add them to your Friends list, join their servers, or even find a casual clan.
One thing I've noticed that many people don't do is use their clan's chatroom. Either in the massive clans (like Whirlpool) or in smaller ones, whenever I'm on the clan page checking out whoever sent me an invite, or the group that my friend is in, noone's having a talk. Which is disappointing, because the group I'm in uses the chat all the time, and we find it to be amazingly beneficial to coordination of gameplay and general bonding between members. Highly recommend Steam's community overlay and all features that are involved with it.
Other than that little addition I felt compelled to make, your review was pretty good. I try hard to be helpful when I play, and if someone tells me they're new, great. New people are what keeps the game going strong. Hope to see you keep playing, Serendipity.
Oh, and Heavy's achievement pack will be out soon (hopefully in the next month or two). To date, two classes which noone played (Medic and Pyro) have recieved updates containing 30-35 Achievements, and some weapons which are unlocked once you have 10/15/20 achievements. These weapons aren't "better", but offer drawbacks. For example, the Medic, upon reaching 15 achievements, recieves the Kritzkreig, which replaces the standard Uber, which is 10 seconds of invulnerability, with what I like to call the Kruber, which gives 10 seconds of 100% critical hits (~300% damage). It doesn't give invulnerability, so it's useless against Sentries or in the face of a Pyro, but in the right situations, it's brilliant. Seeing an allied Soldier or Heavy annihilate four to eight players in the space of 10 seconds is an awesome sight to behold, and an amazing boost for whichever team you're on.