Hi Tony,
Just got back from a long weekend in Dublin two weeks ago!
When is old too old was your question. I think that is not an age but an attitude matter. As long as you feel young, vibrant and able to energize the crowd you are not too old in my book. I am going 52 (april) and still on the game, actually gearing up for my second (well more like 5th) wind.
The gear question has a three part answer, imho.
1) You should figure out what kind of DJ you are/want to be and what workflow goes with that (i.e. what things will you need to be able to do to succeed in your endeavours). Then you need to figure out what software will work best for you in accommodating your workflow. Finally you take all this information and a list of demands and wishes and create a shortlist of controllers that fit in your budget. Only then do you pick a controller. Going the other way around, asking is this or that controller good for … xyz … is not the way to the best results, imho.
2) If you are good at what you do, you can make a party with a box of matchsticks and some rubber bands, metaphorically speaking. So, the idea of stuff being pro enough in itself is not too relevant. What the person operating the gear can get out of it determines if the resulting performance is professional enough for the purpose.
3) Gear-specific. I have sold a few customers the VMS, but they were mostly bedroom DJs and/or fitness clubs that used them for spinning lessons and such. It’s not really bad gear, but it wouldn’t be my first choice for a pro mobile DJ. I do mainly mobile gigs and while I currently own a DDJ-SX (result of a gear swap 😀 ), I want to go back to what I personally believe is the best mobile DJ controller around, the Denon MC6000mk2. It comes with Serato, but works well with Mixvibes Cross (my software of choice) and I believe it also works with Virtual DJ, giving you 3 out 4 major DJ Software options. If you decide that Traktor should be your software, best advice is to stay with S4 or S8 controllers. The integration between non-NI hardware and Traktor software is getting worse, not better.
Hope that helps some.