See above question. The other friend’s family is very laid back. Can I just go along with them or do I have to keep my usual minhagim?

I assume that as opposed to the question above, you mean this family is more lenient than you are, yet you would like to be with them since you will be consuming your own food and diet. Horav Shlomo Miller’s Shlit’a opinion is that in need you can do so.