Given that I have recovered an unsent raw transaction and posted a redacted version of the output above, is there anything obviously wrong with it?
I don't see anything obviously wrong with it. There's a transaction fee and, assuming that the input you are spending is actually 50 BTC, there's no need for a change address.
if there is any advantage to trying to make a raw transaction from scratch, in the way that you describe?
The advantage that you are more likely to create the transaction correctly. However yours looks correct, so there shouldn't be any problems.