On the reports, correct me if i'm wrong but an old report will end up showing 2 sets of coords. 1 with battle coords and the other under his name showing his current coords. then of course theirs the captains log. The resource trick though I don't think it would work. Simply being since many of us use the 100k raid fake. Havens still turn up green after raiding and still show up in the enemies list.
the whirlpools though as stated above weren't created to defend ourselves. They were just given to us as an additional tool. when they were first introduced many of us used them specifically to move our havens to bot lines for easy raids. This actually benefited players especially those on the outskirts of the map that had 1hr+ travel times. But in the end its nothing more than a tool nothing more. Use it for offense, raiding, presidio/bastion defense or try to run and hide.
Your best solution however is 2 things
1. get help from your brotherhood.
2. use his blockade times against him. he's given you the time frames when he's online. A little research and you can take the fight to him and all he gets is a measly ransom which doesn't account for much.
p.s. if you think he's using you for the weekly ransom fame board. after learning his online times you can easily mess him up so he misses out on collections and plausibly loses a top 3 or top 10 spot on the board