For a fair coin toss game, both prob(ruin) & prob(consecutive losses) increases with no. of trials.

Is the Rate of ruin .i.e.where prob(ruin) changes fastest, affected most by the number of consecutive losses?

If so, what is optimal N, maximum no. of consecutive losses to indicate a good time to exit the game?

In a bias coin toss game where prob(head)=0.7, what is the probability 30 heads clustering

(not necessary consecutively) in the first 50 tosses out of 100 trials?

Appreciate any suggestions.