I've been playing HL2DM (frequently) for about a month now, though I've played for an hour here and there for several years. From the people I've talked to, most of the player base seems to have been playing for a long time. However, lately my skill's gone way up. I can grav-nade every time, can Combine ball grab (and speedball) I can overbounce straight but for some reason when I incorporate strafe I stop. I'm still working on that. I'm a mean shot with grenades and .357.
Regarding spawn killing, if someone spawns right in front of me, I'm going to kill them. A stunstick, grenades, and a grav gun are enough to kill anyone. I do have a problem with someone camping spawn sites, or any camping for that matter. I'm not sure what you mean by excessive spam, but I'm inclined to say I don't really care as it's only the spammer hurting themselves by not developing other skills. As for chat spam, I don't like it one bit when it's NOOB this and WTFHAX that, but "ns" type stuff is absolutely fine. In fact, the latter sort of chatter makes the game much more fun.
I know I'm not good enough for CAL, but that's the level of skill I'm aiming for.. why not aim for the top? As for right now, I'm mostly looking for a place to call home and a crew to get to know and hang out with. I want to be with a group that will help me improve, and perhaps do clan matches. Wherever I end up, it will be because it's a good fit both ways and I'll stay unless something goes horribly awry. I was in the same WoW guild from Dec. '05 until June '08.. I'm not a guild/clan hopper.
I'm just a guy looking for a mature, fun clan to improve in and represent in the world and hopefully in some clan matches.