For the first set:
To make it a point to do something means to make sure something in particular happens. Usually it refers to some habitual action, ie. I make it a point to be on time.
For (a), I am not sure what the action is. What will we do with these questions?
For (b), it is clear. If someone helps you, you should make sure to thank them.
It is also clear for (c). You should make sure to do your homework before class.
(d) doesn't really fit this pattern. You can say that you made it a point that you were not attending the party. This emphasizes your efforts to make it clear you will not attend the party.
For the second set:
(a) is mostly fine, but you may consider matching the tenses of the verbs, ie. I cannot make sense of what you are asking me, or I couldn't make sense of what you were asking me.
(b) is fine to me.
(c) has some errors. I would revise it to 'When some people speak too quickly, I cannot keep up with them or make any sense of what they're trying to communicate.'
(d) the first sentence is OK, but the second part, 'I can't speak anything', seems incomplete. I don't think the word 'speak' is a transitive verb that accepts an object. You can say things like 'I speak English,' but I think that is short hand for 'I speak in English.' Here, you probably need to say 'I can't speak (language name)'. If, for example, the language was 'Russian,' you could say 'I can't speak Russian at all'
(e) is fine to me.