There are definitely ways around that. Don't get me wrong, sometimes the board setup and the settlement placements just leave someone with a really bad starting spot. More often than not, there is Always a way, via ports/development cards. It should also be the responsibility of the rest of the players to constantly target whoever is obviously doing better. In the beginning this can be difficult to gauge, but mid game there should be at least one(or two) person distinctly winning. Even the person in 2nd should not be stealing from others (unless there is a clear advantage to doing so, like knowing that another person has a resource you need.)
Stealing from someone the first roll is completely legit, however, in house-games, for the sake of fun we agree not to steal the first bit. ELOs up to Platinum online can be somewhat welcoming to this idea, but generally above that, it's a cutthroat game. Someone who has a 6 ore for example starting point is almost certain to get stolen from. It's just that strong of a spot, players know that as soon as the city gets built, it's an uphill battle.
As a guideline - If someone is getting a city after3 rounds of rolling, they are Definitely the target. Make use of ports.
I've played many games where i got cut off on really bad numbers. End up winning with 11 development cards and a port.
Your boys will make excellent negotiators and tacticians if they get good at the game!
For custom matches you can pick whatever you want. For auto matches you are SUPPOSED to be able to filter out games you don't want to play, but there have been several complaints here and on the Discord server about getting games that were excluded in the options.
To answer your question, no. The Intrigue Progress Card states, "You may displace one of your opponent's knights, without using a knight of your own. The knight must be on an intersection connected to one of your ROADS or lines of ships." So your opponent has to put down a road on the board that would connect him/her to your knight directly.
You'll need to buy the base game to play the basic scenario (or variants like "Ore for Wool" and "Harbormaster" that are included in the base game) with a randomized board in all game modes. Your fellow players in multiplayer games will need the base game for this as well. The base game and expansions are 500 Catan Gold each. If you still have your registration bonus of 100 Catan Gold, you'll just need the 400 Catan Gold purchase for 3,99.
We currently do not offer a larger board (5/6 player variant) for the base game. However, if you like larger scenarios, there are various included in the Seafarers expansion, e.g. "Greater Catan".