This could be a tough game, especially for the 20K goal!
I have few fixed plans at this point. Much depends on how the game unfolds. Particularly important is the question of whether we're isolated or not.
It sure would be nice to find some bonuses in the starting area. I'll start by moving my scout N, and then almost certainly NW to the mountain. (I've picked north for the scout both because of the number of tiles which will be exposed and because north seems most promising for contact with another Civ.) After moving the scout all depends on what's seen, I'm not making fixed plans beyond that, there are too many possibilities to worry about them ahead of time.
Initial research: Our starting techs aren't very useful for starting with 40 turn research - we can't start working on a deep tech. If we're not alone then France and England are fairly likely neighbors and they'd have Alphabet right away. But if we are alone, starting with Alphabet (heading for Map Making) could be a priority.
There's another important factor affecting the research choice. If going for 20K, note that our starting techs don't enable any large scale prebuilding of wonders! This isn't often a factor in a game but Masonry is required to build Palace. If not using the capital as the 20K city, the ability to prebuild via Palace is desirable.
I figure the research decision is best made on the assumption we're alone. (If we're not then early research on anything is likely to be wasted and not matter.) I'm going to start by researching Masonry at 100%. If we're alone I want to be able to prebuild Palace in a 20K city before I could get through the Alphabet->Writing->MapMaking (or ->Literature) sequence. (Note: there's a small chance I'll change my mind on even this during the opening moves - perhaps the capital location will seem ideal for the 20K city. But low odds on this for me.)
Initial build sequence: I don't have a firm plan, it depends on what becomes visible in the first few turns. If it looks like we're in a very limited land area I may not even build a second scout. I may want a granary before the first settler. But an early warrior or two is likely to be important for barbarian control (less so if there are neighbors helping to patrol.) And I won't want to delay the first settler for long after growing to size three. My most likely build sequence is a few units (mix of warriors and scouts) then settler.
About early wonders: I think that with these map settings, the chance of getting the earliest wonders is low. An OCC might have a better chance at one of the first wonders though it will have a hard time later on. A multiple city game will want to pump at least one settler from the capital first. After doing that, getting an early wonder such as Colossus seems unlikely to me. And quite unlikely for Predators.
About Berserks: It seems to me that these guys are overpriced. But they could be very useful if the map creates a particular kind of opportunity: they can sometimes effectively be a three or four tile attack unit. Three for the boat carrying them, then wake them up and move another tile in the attack. If there are opportunities for this, the changed naval movement will add an interesting twist

Berserks could also end up being good timing for a Golden Age.
I'm planning to start by shooting for the 20K goal. It could be a very difficult one on this map. I may change my mind about the goal during the game
