Guys if I want to try my luck and point some miners from Nicehash at this pool is it better to run at high speed and use my credit quickly or slow it down to make my credit last longer.
For example if I want to spend 0.1BTC I can set the speed to 1 GH/s and my credit will last 36 hours.
Or I can set the speed at 3 GH/s and my credit will last 12 hours.
Which has the greatest chance to find a block?
Either you misread, mistyped, or would be getting ripped off (that price will get you hundreds of TH on miningrigrentals).
That aside, the answer is that it doesn't matter. 1x for 36 hours and 3x for 12 hours will submit the same number of shares.