Hello native English speakers
1. Thanks for sending the letter for me , it saved me a trip.
2. Thanks for sending the letter for me , which saved me a trip.
3. Thanks for sending the letter for me , this/ saved me a trip.
The following is a noun phrase rather than a sentence:
4.① loving into your heart for doing that thing.
4.② loving into her heart on doing that thing.
4.③ loving into Tom's heart for doing that thing for her. ( for this phrase, the context is : Jane loved Tom into his heart for Tom's doing that thing for her.)
Question: Which is/are grammatically correct, 1,2, or 3?
And 4 ①,②, or ③?
(Hope to correct if being wrong.)