Learn English – How to use Would Rather

This is fine. The present > future pattern is 'usual' only in conditional constructions:

If he does this, I will do that.

In these the 'tense' forms aren't really time references. I will do isn't any more futurive than the does - it signifies subsequence or consequence relative to the if clause rather than an actual temporal relationship to the time of utterance.

In other contexts, the restrictions on using future constructions in consecutive clauses are logical and factual, not grammatical. All of these are OK:

He will do this and I will do that.
He will do this to insure that I will do that.
He will do this, consequently I will do that.

As for the question TecBrat raises:
In your first sentence, the can is only 'present' tense in form; its reference is just as futurive as the will in your second sentence. The fact is, English doesn't have a 'present' form, despite the name. The two tenses in English verb forms are not past and present but past and non-past, and the 'present' form can be used with either present or future reference.

I'm in your neighbourhood tomorrow evening—want to get together for a drink?

When you get right down to it, this is the only way to express future reference with can. Full modal verbs like can cannot be used with auxiliaries like will and be and have, because they are defective—they do not have the non-finite forms (infinitive and participles) which the auxiliaries require.

Since English doesn't have a future tense, somebody has to do it.

Will and shall are auxillary verbs that are used, among other things, to refer to future time. They attach to the noun as 'll.

Regarding your questions:

It is grammatical.

It is covered in textbooks (example).

Yes, you can say:

Then you call me and tell me where you are and I'll join you.

Strictly speaking I'll join you is not using a future tense.