with the ascending alternating high and low notes at the beginning - i think they could be less 'regular' in terms of exact phrasing and dynamics. more shadings as they go up. not just - loud/soft for high/low. (ie how you go up a few bars later -pp/mp, mp/p, mf/mp, f/mf, ff/f)
i find this piece dry, too. i'd add a bit more pedal in the staccato mid-section. you're obviously ready for it. it will soften the harsh sound. maybe some pure classicists would want it to sound lighter, but you can still play light with the pedal, imo.
i would say i get the most tense when i hear the turns, etc. because when you do several in a row - they make me get tenser instead of relax. maybe to relax your audience you shouldn't think of 'perfection' only - but an expression through each one.
i realize that haydn and mozart are very hard to play from memory because everything sticks out and sometimes things we don't intend come out when we think something different in our heads.
also, i tend to think 'blah blah' when i hear triplets played exactly the same each time. whenever you have anything repetitive in haydn - you've got to 'do something with it.' that's my humble opinion. but, really, in reality - i don't think i could play this anywhere near what you are doing right now - so - just answering your questions and not really trying to one- up u.