What are the main opinions regarding hitbodedut? I strongly recall being taught we're not supposed to bother Hashem more than three times a day, though I can't find an actual prohibition anywhere.
There is ample evidence that Gedolei Yisroel "bothered" Hashem more than three times a day. First, there is the Gemara Berachos 28b and 54a (Mishna 9:1) that teaches we should say a tefila at every juncture of uncertainty throughout the day. Then there is the mitzvah to say 100 berachos per day. And on and on. Regarding hisbodedus specifically, the Mishna Berura mentions it in passing in 111:2 as something that appears completely permissible.