Six months ahead of the naming of any test squad is a long way off to be guessing but I like some of what you have suggested - especially the captaincy going to Da Silva, he would have been my choice ahead of Roston Chase - who I like as a white ball player but nothing more. Chase simply must go.
Despite his lack of runs, I'd persist with Tevin Imlach behind the stumps as he is a much better keeper and that is his primary role - alternative keeper-batsmen will give you what? An extra 10 runs? Not worth it for what will be lost behind the stumps.
Need one proper opening batsman to go with King, I'd bat Greaves in the middle.
Need to see a batsman or two make the step up to help out this brittle unit - the bowling is fine and should be for the next few years - but the regional set up, as we have discussed, is not structured in a way to assist the promising youngsters and help them climb up the ladder.
Again, I'll share my thoughts:
Shorter regional championship - one round of matches played on best pitches
Followed immediately by Headley-Weekes format tournament - pit the best against the best
A team schedule increase - MUST be of paramount focus
These steps will squeeze the talent to the top and should harder their resolve during the process. No more mediocrity being rewarded by a place in the test squad.