You might make = later on in the future, and is conditional You might be making = right now.

"You might be making Max a little nervous" means someone is doing something right now that is probably making Max nervous. "be making" means present time ....NOW. If you say "you might make Max a little nervous" that might mean tomorrow, or next week, if you say something you might make him a little nervous. If you do something (in the future) he might get nervous.

The word "making" is used because you're in the process (at the exact moment) of making Max nervous. That's just the nature of "ing" ending verb tenses. Some other examples would be: "You're making a mess!" "I'm making one last try" "She is making plans for the weekend." "You might make Max a little nervous" is actually awkward. So, "making" is correct and natural. As for "might be doing," it's the same concept. "You might be doing this correctly for once." "We might be doing a favor for our friend." Just remember "ing" ending verbs mean "in the process of."

Good question! 1 -"that is I think you might be making Max a little nervous." 2 - why don't we say "you might make Max a little nervous"? 1 = something is happening now 2 = it sounds conditional/ if you do something it might/or might not make Max nervous. The important part of understanding this sentence is in the number 1 example, "That is". "That is" is another way of saying, "in other words" or "I'm really trying to say" or to be even more clear, "I AM SAYING!!!" haha it's a type of expression that is used in English when people are trying to be suggestive or delicate to a social situation, or use diplomacy. If you look before "that is" in the book where you got this sentence from, you'll get a good idea of the context. It will probably be something like (Imagine a party), "I don't know that you being here tonight is for the best, that is, I think you might be making Max nervous". They are trying to carefully say, "Look! Go home, Max wont want you here". If they are at the party when they say number 1 Number 2 would be before the party, "I don't know if you should go, you might make Max nervous" That is, (important comma) I think you might be making Max a little nervous "What I'm really saying is, you ARE making Max nervous, go away" SO 1 = you ARE making him nervous 2 = if you go to the party you MIGHT make him nervous It's English manners, decorum, diplomacy, sensitivity - I hope that example really helps x