Oh shit I didn't know that Kamchatka/Alaska trick.
Yeah I'm playing as Oda Bakufu, I have claims on Kamchatka but decided it's really not worth the hassle to grab what are essentially worthless tribal land.
When I first sent ships to California I just right click to Baja California and by the time I got there my ships were in desperate shape. I think they go through the ocean, bypassing Hawaii (which I have since conquered purely as a stop for my ship)
Yes, this land probably won't give you much income. (Although some provinces have expensive trade goods, eg. fur/copper, which can be quite profitable as TCs with manufactories.) However, as a fleet base giving easy access between your homeland and colonies, it's priceless
Routinely stopping off in Hawaii is IMO a bad idea (unless speed is essential) because it's surrounded by ocean tiles, which cause massive attrition the moment your ships enter. However,
conquering Hawaii is worthwhile IMO because it has a centre of trade in a TC area, meaning it's useful for getting another merchant.
As a general point, a single right-click is almost always a bad way to move your ships. This always sends them via the "fastest" route, which usually means via several ocean tiles and/or headfirst into a massive enemy fleet. (North Sea and Bay of Biscay, I'm looking at you...) Ships are expensive enough and annoying enough to replace that IMO you
always need to give them a custom path, because different situations will call for different tradeoffs between speed/danger/attrition. (Just like armies.)
So I should just stick to defending my Japanese possessions and Australia?
IMO, yes.
And maybe also station a medium-sized army in each of your American colonies because, if they are large and full-occupied, they will provide some warscore to Spain and long occupations might cause instability (devasation/rebellions/etc). And it may be possible to rack up warscore from battles vs tiny Spanish colonial armies. However, if Spain and their colonies are powerful and are swarming you in the Americas (because they can walk there), it may be better to simply leave your colonies to be occupied.
(I know this wasn't directed at me, but I think
@grotaclas' answer will be similar.)