What can be listed as "invited talks" on your CV?
Your first question is addressed in the answers to this question mentioned in the comments: Difference between contributed and invited talk

Namely, it is standard to list seminar talks under the heading of "Invited talks", so you should do this.  Some people separate conference talks vs colloquium talks vs seminar talks under appropriate subheadings.  I don't know whether it's standard in your field for junior people to do this, but you could try asking colleagues.  I am in pure math, and I don't, though at some point I started margin symbols to highlight conference talks.

For your second question, it depends upon the reviewer, but in my mind there is some value in seeing a bunch of seminar talks.  It means if we fund you, you'll be active in telling people about the research we've funded, so that's a positive.  It's of course not a primary deciding factor, but grants are competitive so even small positives can make a difference, so it is certainly worth listing your seminar talks on your CV  (assuming you're talking about applications where you send a standard CV, rather than a mini-CV with page/content limits).