Thunderroad

Sounds like what you're doing is fine. As you may be aware, Chase has a 5/24 rule which, to make a long story short, means that if you're relatively new to this game you might want to make your first five cards Chase because you can't get new cards from them if you've signed up for five of any kinds of credit cards over the course of the previous two years.

The bigger lesson, though, is that unless you're spending and traveling a lot the main value of new credit cards is the 40,000-100,000 miles/points sign-up bonuses you get for spending, say, $3,000 in three months.

Getting different credit cards from different banks really isn't a problem, since the best way to use those points is to convert them to various airline programs anyway. For example, Chase, Citi and Amex points can all be converted into Singapore Airline miles, which can in turn be used to book United award flights (assuming United award availability, which is a big if) or awards on other Star Alliance partners (though that's less relevant to you, given that you don't travel much beyond the USA and the Caribbean). But even if you don't redeem for awards, and simply use those Chase/Citi/Amex points directly for flights, there's no problem with diversifying.

One other option that might work well for you is Alaska credit cards, since its miles can be used on various airline including American and perhaps Hawaiian.

Not sure of the answer to your question re getting more points for the Chase Reserve upgrade. You might try posting it in the Chase credit card forum here.

Given your limited travel, the higher fees for the Reserve or the Amex Platinum probably aren't worth it.

Hope this helps!