Welcome! Its actually my first time running it too. The roundtrip for NearEastland takes two turns total, rather then 4. At the current market value, each share is worth 0.5 when it docks in port, so you're generating 0.25 profit a turn.
Let's say someone takes Kashyyk's loan of 2 sovereigns. That merchant then goes all in on a ship with their existing 3 Sovereigns. Following the current trend in contracts of 10 shares per boat, they would own 50% of its proceeds when it came back to port, so 2.5 Sovereigns when the goods sold at current market rate. They could immediately pay 2.2 Sovereigns back to Kashyyk, and they'd still own 50% of a boat. They have only made 0.3 profit, but next trip they are loan free and still get a lion's share of that boat's proceeds, assuming nothing bad happens.
Same deal if they get loaned 1 sovereign. They invest in a boat for 2 sovereigns and maybe a second boat for 2 sovereigns. They only have to pay Kashkow Enterprises back 1.1, but boom they're involved in two ships, so they're at less risk.
TricMagic's loans were more expensive, instead of a 10% increase you had to pay back 50%. But the benefit was if one person took the loan you wouldn't need 4 people to buy a boat, and at the time that was the only loan option available, and not many contracts for buying boats. You could also take a 3 sovereign loan which would give you a 60% share in a boat if you went all in. If you did that. 50% of your profits would go to paying off your loan in the first turn, and you would still be paying for four turns after, at an increased rate. But by the time you were loan free you would have about 4 Sovereigns in the bank, so presumably you could start buying shares of the boat to own 100% or get 40% in a new boat, if you wanted and could convince your fellow shareholders. That being said, alot can happen in 4 turns - new stuff to buy and bid on ect. On the more expensive loan repayment turns, you'd still be getting a little under a share and a half of profit. It's up to you what your threshold on that is.
Yep! If things went wrong in the journey Kashyyk's loan would be in danger as well, if the player had no shares in any other boats. Kashyyk is loaning 2 Sovereigns out of his 3, so presuming if the person who takes the loan isn't on the same contract as him, he won't go bankrupt at least. That's why TricMagic's 3 Sovereign loan had a hefty repayment plan on it, two people would be going all in and if that went wrong he would have no way of generating revenue unless he took a loan.
On sea charts, full rules will be introduced a bit later for you to peruse:
There will be opportunities to hire explorers. Explorers will accept donations for voyages to find new islands. They will have a threshold for 'exclusivity rights'. You can bid as an individual merchant or with your company. The sea charts are not linked in ownership to a specific ship, unless a contract was drawn and agreed to that states that. If you outbid everyone for exclusivity rights for a ship as a merchant, it would go to your inventory to do with as you like. If your company decided to bid together for exclusivity rights, there might be terms hashed out to agree how your company would utilise them. It would even be possible for a company without a ship to buy exclusivity rights, and then companies might be negotiating with them to get access to the charts or have them rented to them.
It does appear Happy Crabs LLC can buy out our shares in port with 10% additional compensation, by nothing to stop you attempting to by a new ship with others if you did got bought out. Also, at current rates Happy Crabs LLC would make 1.5 profit off the Audacious Crustaceous, so even if he did decide to buy someone out first turn (and there is a grace period of an additional turn), he can only buy 1 share at 1.1. likely more of a long term thing.
As for determining which island your ship is voting, you can discuss with your fellow shareholders, vote, Swordfight, pick randomly on a map. When an agreement is made, one person needs to use ACTACTACT: to set the new course before the next turn.
First turn will have a bit of 'I do nothing/wait/pass' but as mechanics are added I hope the waiting game lessens a bit.
Hope that helps!