It's a personal decision. I'd recommend asking for a CLI w/your SSFCU CC. It's been open 3 yrs and you're only at $1k.

You might want to look at adding an Amex. I'm not sure if you'd qualify for a BCE, but it has really good rewards. You might want to start w/Zync for only $25/yr AF. Then in a year, app for BCE. Also, this way all future Amex will be backdated to your first Amex. The benefit of that is that usually when you get a new CC, your AAoA takes a hit. With backdating, your AAoA actually gets a boost, which helps your FICO.

Beyond that, I'd think about what you're looking for in terms of rewards. Navy is actually pretty good, IMO. Some have higher % for certain categories, but I like Navy for my all-purpose card. It's a straight forward 1% cash back and you only need to accumulate $20 in rewards before you can redeem.

You might be able to qualify for Chase Freedom, which has different 5% categories each quarter.

I don't think you have too many cards at all. You might want to close your Cap One at some point if there's an AF, since your CL probably won't ever increase.