I've done a fair bit of solo slooping, including doing the whole 5 Order of Souls and 5 Gold Hoarders voyages in the roar solo. (had 3 GH voyages in a row with crying chest -.-)
It's pretty much impossible to defeat an galleon/brigantine of skeletons or players on your own, especially when you have some loots on your ship.
That's the way it should be a group of 3 or 4 people should be able to defeat one person. Why should a solo player be able to be able to defeat and sink a ship with more people? What does having loot on your ship have to do with this it doesn't slow your ship or anything this part makes no sense at all? Skeleton ship difficulty is already based on ship size at least the ones that spawn on you are and you shouldn't be going after the roaming PASSIVE ones if you can't defeat the one that spawn on you.
The fights against skeletons in fortresses are annoying and long, and you die a lot because each time, some of them have powder barrel so it take a very long time (at least 30 minutes) so that way, others ships can come, sink your ship and get the loots (of course, none of them offers you an alliance, it happens only once for me, in 300+ hours of game).
Fortresses aren't designed with solo players in mind nor should they be it's a fun challenge to solo a fortress. I've seen galleons take ages to clear a fortress and cleared one out solo in about 10 min (granted they were all basic sword/unarmed skeletons) it's all a matter of skill and wave luck. It's risk vs reward if you want the reward of doing a fortress you have to accept the risk of being sunk while there.
-you got the same amount of money when you sell something, why ? ($100 for a crew of 1, 4$100=$400 for a crew of 4, not logical)*
It's the way the game works, everything has a price range that stays the same no matter how big or small the crew money is pretty much meaningless anyway
-your ship is the slowest so you can't escape
Sloop is fastest against the wind use that to your advantage
-your time of spawn is equal to other players so your death is more punishing that others
That is as it should be you shouldn't get a faster spawn time just because you're solo.
-fights against skeletons/krakens/megalodons with same amount of skeletons/life
The skele ships, karens and megs are all based on ship size already and are easy to deal with solo with a stocked ship unless they come together. if you don't want to fight a Meg just sail close to an island/rock and it'll leave. Karen is a joke and is defeated quickly. Skelly ships sink fast stay close to them so they can't shoot you and put holes in them and they'll sink with minimal damage to you.
Others things are annoying and, in my opinion, useless in this game:
-the fog : ok, it is impressive the first time you get in there, but it is way too big, and you don't see anything even if your are on your mast.
-the tempest : same as fog, it is too big, most of players, especially single player will avoid it or wait until it passed. And why is there always a tempest ? Can't it appear, last 12/24 hour and the disappear ?
-the Devil's Roar : wow great ! a new zone, I can't wait to explore it. Two hours later : I would never want to go there again : volcanoes hit you, 3 holes on your ship, if your are not on your sloop, it will sink in 30 seconds, great. Geysers and earthquakes are also annoying.
Fog, slow your ship and check your map regularly it's not that bad. Storm just go around it, it's not that big if the island you need to go to is in it just go do another island 1st or suck it up and go through it's a lot better than it used to be when the lightning had aimbot. The Devil's Roar is great I love it there once again it's a risk vs reward situation.
There also could be more events on the map like 2 fortresses can be active at once so several people could have the choice.
Fortresses already re spawn way to fast and having 2 on the map isn't going to help you as a solo player when you're already taking 30+ mins to clear it a decent galleon crew could clear the other and come to yours well before you're finished or they could come to yours 1st then what you now want 3 on the map? as i said earlier you want to do fortresses solo that's fine but you have to accept the risk that comes with it.
There also could be trade between pirates why can't your give money or quests to others players ?
Why would you need to trade money or voyages? Money comes fast and once you get the cosmetics you want it just sits there accumulating doing nothing.
If you want to solo on SoT feel free but don't complain about it being so difficult when you're playing on the hardest setting as it were. There are plenty of ways to find people to play with if you don't want to solo and open crew if you get some terrible/lazy players just leave and try again you can also find great players to make friends with and sail with again.