Your use of not using "to" before "home" as it is an adverb is correct, as well as your second statement. That use of "You come to home" is really, really strange and I've never heard that before. It seems to be a typo. I would say "You come home and you want to tell your brother what your friend told you." Either that or "You come to your home...", though the first one is much more natural.
Anyways, to answer your question, here are a couple of SE posts!
https://english.stackexchange.com/questions/33652/why-is-to-not-used-before-home
This one details how the word "home" functions in several ways (how it can be either a noun or an adverb).
Can we use "to" before home, if we are using determiners (her, my, your etc.) before home?
The second explanation is very, very good. It details how "home" acts when bare and surrounded by other things.
I hope this helps, and feel free to ask if you have any more questions or if I didn't answer properly! :)
I'm a native English speaker, from the Midwest (US), if that counts for anything. There are variances in language, so if this is a regional thing, I don't know about it and I apologize for that.
You should notice that in all the sentences you wrote and assumed that the preposition is missing, the prepositions are not missing. This is in accordance with the grammar rule. You see before home, here, there, prepositions are missing, because home, here and there are adverbs. And therefore we don't need a preposition before an adverb.
You can also check this link
Hope this helps.
Best Answer
Either is fine, although they might have very slightly different nuances. I think of switching to something as having more emphasis on throwing out or not using the original thing anymore, while switching for has more of an emphasis on the transaction. Functionally, though, they're interchangeable (though you might need slightly different wording based on the context), and I'd probably say something like this:
You could also say "switch to ones that fit better".