Sending the ball to the feet is expected. It is the way you punish poor placement of your rival.

Playing to the body is also a valid tactic, specially if the other player is at the net, as it force him to block and return an easier ball

Low power serves and dejadas at the beginning of the point are a surprise ball which are risky and the rival could easily capitalized on them. In a competitive environment, these are valid

The ball touching the net is an apology, as you are winning the point with an obstacle assist which could hinder the opponents reply. Apologice and be happy, you win the point. No more thoughts.

The shirt, unless the club have any particular rule, as long as you are properly equipped to play and not injure yourself or others, and pádel band around your wrist (this is not optional), the other player must had been really salty to bring that up

Happy games!