I agree that we tell them how far to our borders and that they are the only team we have met and put in in a way that would lean on them to tell us if they've met anyone else.
I agree, we should do that right away, while we discuss the other stuff. May be a short introductory letter from you SilCon "introducing yourself" as the AMAZON Diplomat. You could express a desire to be friends, share information and discuss a trading partnership. Share the info above as a "gesture of goodwill" and gently ask them about the same. If they respond honestly. That suggests a possible good partner. If they obfiscate, lie, stall or avoid the question, this might give away hostile intent towards us. At a minimum, it will show that they are not trustworthy, and thus not a good candidate for an ally.
I think we should definitely show a strong interest in perpetrating a tech-trading alliance. Team Sirius was out of the loop on the tech trading alliance last game, and will most likely be very keen to work with us.
Agreed (Although I think you mean Saturn

). LP was stinging about being left out of the last tech alliance and as I have said before, he would be very unlikely to repeat that mistake. As you can see, Sirius built a scout workboat right away... precisely for that reason. They are Looking for a tech alliance early on... that is WHY they probably sent out the wb so early. And we should not drag our feet in recognizing and taking advantage of this.
For us an expansion oriented team, speeding up tech rate through a tech alliance while we expand faster than others is the way to go.
This is the Key for us. We are NOT FIN, so we CAN NOT keep up in tech on our own. We have to convince a FIN civ to be our tech workhorse, while we expand relentlessly. Team Cavalieros used this strategy to perfection in the last game.
A NAP is not directly of use, but it forges the bond stronger, cementing the alliance. I suggest we support the idea of a auto-renewing NAP with a cool-down period. I think this is a good to show support and to build trust.
Agreed, this should go in the first letter to them. Hopefully something can be sent out soon (today?

). As I have mentioned earlier, LP responds favorably to frequent contact. Especially Swift, swift, responses to his communications. He will not appreciate "long careful deliberation time" by us.
Open Borders are not so useful at this point... it will only be helpful if we have to pass through Sirius's culture to advance Jenny.
OB is useless TO THEM, because they don't need OB to pass our city... But they dont know that... they may be concerned that they will need OB to pass our borders. Plus, They will be unlikely to refuse OB because they know that it will be seen as a sign of hostility.
On the Other hand, by the time we reach THEIR borders, we might need OB to pass by. Don't dismiss the possibility that they chose wb as their FIRST build. Remember LP was probably paranoid about being left out of the trading loop in this game because of what happened last game. IIRC Sirius had a high Manufacturing rate at the beginning of the game. They may have worked a forest hill to get out a wb fast, which would explain why they seem a little behind in tech... and why the city did not grow while the wb was being built.
If they built a wb first, then Voyager is closer to us than Jenny is to them and their border may pop again BEFORE we can pass it. In that case, we will need OB or permisson to DoW (Declaration of War) just for the purposes of sailing through, with Jenny (if neither of us has Writing yet). We should offer such an agreement to them right away, BEFORE they realize they have reached the other side of the landmass. Finally, they can not use OB to enter our land anyway, because their wb can't enter ocean tiles. Even ones of countries they have OB with.
We should also gently suggest that they tech Writing so that we can make our OB official, and DoWs unnecessary. Mentioning Writing gives away that we don't have it, but they probably know this anyway, and we will need to give away some info to engender trust. We could also gently ask about their plans to get Alpha so that we can "cooperate towards shared tech goals" or "enter a tech trading alliance"
if we'd rather not get involved with Sirius for other reasons...
I have some concerns in this area, but I'd rather not "poison the well" by discussing them in detail until it (if ever) becomes relevant. For now, we should really just treat Sirius as our first potential ally in what will hopefully quickly become a lopsided 4 on 1 or 5 on 1 alliance. The best way forward is to keep forming and reforming lopsided alliances to elimminate the odd man out while we keep out-expanding everyone.