The ideas of taking the smaller islands, Kinmen and Penghu, or a blockade make no sense to me. Why would the Chinese want to delay the inevitable even further? The best case scenario for China is a successful invasion that forces the Taiwanese government to negotiate for peace. That way they don't drag out the conflict and achieve their goals of bring Taiwan back into the fold, even if they give Taiwan some concessions. I assume the Chinese would rather have that, then a long drawn out blockade that gives ample time for the US to respond. I'm glad the former admiral brought that up.You probably heard of Lyle Goldstein or read one of his articles.
I think the US is doing everything right and there is few options that are realistic that they are missing. Missiles in the second island chain are a good idea, but why would Japan agree? Japanese involvement would frankly increase support for the war.