"I am hoping" or "I am guessing" and "I hope" or "I guess" have the same meanings, the difference is that when you use "ing" you are talking about the present moment, like you are sitting in a cafe with a friend and you say "I am hoping that the weather will be nice". When you don't use "ing" and you just say "I hope", you are being more general (it not about the present moment anymore", like you say "I hope this president is a good person". I hope it helps ;)

"I hope/guess that..." and "I'm hoping/guessing that..." are basically the same and can be used interchangeably. Please note I added the word "that" to these set phrases in order to make your use of them easy and in their most common form.