Well, I would rather build curraghs than swords and explore more aggressively (with suicide curraghs, some of them lost on ocean).
1) I would build the embassy with Japan now (general advice for SG - make screenshot of capital and post in your report, whenever you make an embassy). I'm doubtful, if we can afford the alliance then, so would rather wait for philosophy.
Literature after free tech for sure, but the reason is not trade. We need a library to drive research, that's not a typical deity game, the AI is to slow.
About end of philosophy research:
You didn't say, yes I understand everything, so a small lecture

(maybe unnecessary):
We will research philosophy and get to the pop-up for a new tech.
Select: Show me the big picture (that's the famous big picture screen, often abbreviated as TBP)
From there you can select the diplomacy screen and talk to all AIs.
You can trade already use philosophy to acquire new techs, before you have to select a new tech you can get for free. So one can trade for math, if it is available even that late. Probably there is nothing to gain here in this game, but expect the question "did you go to TBP" in every SGOTM and a big rant, if you have to admit you didn't.
And BTW , if math is available, I would set my money on currency (I want to drive world wide research as fast as possible and currency typically gets researched later), Wotan wants the most expensive tech construction. That's just a gut call, both are pretty good.
Another possibility is that polytheism is available before we get philosophy. Now that's a tricky one. I personally would go for it (will be very expensive) and take monarchy for free. It is an absolute useless tech, but by far the most expensive we could get at that point and distributing it would prevent all of the artificial stupidity to research it. But that is really the klarius method, going for the long term goals and ignoring short term. That's not necessarily the best (eh did I say this).
Still another point under your 1

: chopping jungle is not important currently. One more mining on an irrigated tile would be more important. By that we can work the plains cow instead of the iron hill and still gain 15sh. That's better in the sum of shields and food.
2) We are not building galleys, but dromons and that's a bit of a problem

. This is our unique unit, so we get our golden age, if they win a battle. I would rather not build them now ( and for sure we anyway would build a harbor first, which costs just as much as 1 dromon), but wait until we have something to transport (more than 2 swords). They should for sure
not go out to explore. There is a big danger that we get involved in a war and one of the many curraghs attacks it and we get a golden age. We should have our GA later, when all the AI fall behind us in tech.
A few more general things (not anybody in the team might concur, but I claim in my typical humble manner

, to be the top specialist on high research games in the team).
If anybody demands something, reject. We have to fear nothing and would love them to send a few troops so we can promote our units. Also every declaration is worth 3 happy points (one for every 4 pop) for us in war happiness. It might not be needed right now, but gives other MM options.
Trade for HBR, then give gifts all around, our techs are pretty dead already and we soon will have new ones. The limit on diplomacy is tech and that doesn't mean early techs. The difference between good and and not so good games is typically what techs you can get from the AI in MA and IA. So AA techs should be distributed freely, as long as you still can get all the money around.
Ok, I think I obfuscated everything enough for today, feel free to ask questions (it cannot be that everything I said is clear as Everclear).