Can we use the 'long for doing sth.' pattern or should it always be 'long to do sth.'?
Does the second one sound ackward?

That is the place I have been longing to visit for years.
That is the place I have been longing for visiting for years.

Question

Can we use the 'long for doing sth.' pattern or should it always be 'long to do sth.'?
Does the second one sound ackward?

That is the place I have been longing to visit for years.
That is the place I have been longing for visiting for years.

Answer

No, you can't It's always: "Long to do something".

Answer

Yes, the 2nd sentence is awkward.

"longing to visit" is the correct phrase to use.
You can only "long for" an object.

That place has been longing for me to visit. (The meaning of the sentence is changed here, but this is how "longing for" could be used.)

Answer

It looks like they say "long to do something" and "long for something(noun)", I long for your love... that's very old fashioned, man.