"practice more than I already don't" ..... 
I would definitely say if it's not your main series then points don't count. But yeah the favorite track races j could see being an issue. I think that's why it would be good to declare what tracks your racing at at the beginning of the season so that could all be hashed out. Myself personally I'd love to do a road course like Watkins Glenn when both series are there just to get some more seat time because I suck at road and then maybe Pocono because it's such a unique tricky track.I would enjoy running both series or at least running a couple of races in Xfinity...whatever is allowed. In one season, I just couldn't get used to the Xfinity car and is why I moved back down into trucks. I think with more seat time, I would eventually get more comfortable in the Xfinity car and would prefer to race in that series.
The only issue I see with running as many as you want is having way too many running in certain 'favorite track' races. The only issue I see with running only a couple of races is would this be a nightmare for the one having to keep up with this and the points being counted or not.
There is a slight difference between practicing and learning racecraft. One who has racecraft can survive with little practice but may be slow. One who has no racecraft cannot survive with little practice and will be slow. I don't think it's as much a matter of not enough practice as it is a lack of racecraft.Maybe that's the problem with the trucks is not enough of you are practicing. If you want to be apart of something great, you need to learn to sacrifice a little and give a 100% effort. Prove yourself that you can race in xfinity.
Can't blame a guy for trying.With all due respect gentlemen, this isn't gonna happen, so don't waste anymore calories.