I realize you are primarily discussing on line play. I think that boring your opponent or making them unhappy in the game is harder when you don't even see your opponent, especially if it is someone with whom you are unfamiliar. If it's someone you have familiarity with, then you may be able to play openings they don't like or that orare boring and avoid sharp lines. Furthermore, none of these are inherently wrong or necessarily going to induce boredom or displeasure. If you need a draw to win a prize, they are even quite understandable. What I really want to address under this topic is over the board play, where methods of denying can fun include: