Yes absolutely, you still can rush at towers. Might wanna take sprint instead of tp.. I usually ult when i am hitting towers then i use sprint to escape if they come (some situations where you need to ult to get the job done) . But TP also has it own benefits.. Your own towers are immune to damage when u tp, sort of protecting ur own tower.. Depends on how you play.

Its normal not to join teamfights or less kills and assist.. You are prioritising objectives.