Interference?

Being snowed in has its advantages as I got to play for two hours at a nearby school who's pupils were enjoying the same weather perks as me yesterday. During this relative marathon on the court I became aware of an annoying habit of my opponent of deliberately hitting shots to a place where I'd be obstructed in getting to the ball by his rather large frame. Every time I called for a let he'd say I could have chosen another route to the ball and should shut up. As well as this he also hit quite a few shots where I didn't see the ball at all between leaving his racket and going out of play.

I thought about this during a break from the game and realised that I was purposefully moving after each shot when I thought I was obstructing my opponent's route to the ball. As an experiment for one game I made a point of either holding my ground or moving to the T with a wide low stance and hitting the ball so as to be in the way as much as possible without actually impeding a shot. This aggressive tactic quickly became annoying and probably would have ended in a fight if taken to extremes but I didn't think I was doing much different that what was being done to me.

Obviously there is some compromise to be found here as there isn't enough room on the court to avoid the odd bit of argey-bargey but is using your body as a blocking device to the next shot a fair tactic? The rule in question here, rule 12, says that a player is entitled to "unobstructed direct access to the ball" on his shot. Does this include moving around the court or is it just on the shot? Also is the player who just hit the ball obliged to move in order to give his opponent "clear view of the ball"? I don't like petty squabbles over let calls every other point in what should be friendly games but I'd like to know where I stand, so to speak.