Another long post, sorry. I just get going.
Let me just say you are an excellent scouter, goody huts or no. Having this much map info this early is wonderful. I think it's likely that either it's just you, Augie, and Joao on the continent, or that anyone else is a long way away on the other side of Augie. It's hard to say for sure, but Joao looks cornered on the end of the continent.
And speaking of Joao ... I don't see any strategic resources in his area. I find it unlikely that he has none. That means they're either in the fog of war in his Lisbon's BFC, or you can't see it, because it's iron.
Joao being cornered + Joao maybe not having strategic resources now + Isabella wanting to kick the snot out of Portugal = Joao on a pike. Joao should be rushed.
I don't like the chariot rush, though. A strength of 4 against a unpromoted fortified archer with just 20% cultural defense is 4:5.85 odds, not counting first strike. That sounds like it would require at least 3:1 numerical superiority, (maybe more if the cultural defenses are higher or they have CG I promotions) and even if you had surviving withdrawal chariots, they would be so badly hurt that they would be unable to contribue to a second round of battle, even if the burned a promotion for the healing. Lisbon is heavily forested, so the chariot movement is less usable. I suppose it could work if you threw a lot of trees and population at it right now. Could 10 Chariots built in the next 20-25 turns pull it off?
Personally, the chariot rush has never worked for me unless I had a chariot UU, but I'll defer to those who know better.
Dealing with Joao: I see three options:
(1) Block Joao with two cities (the two spots south and SE of Madrid on EEE Boy's map look good) while teching to Iron Working (then Wheel/Pottery) and hope you find Iron (which I think is possible, given that there are no visible strategic resources near Joao). If there is no Iron, then the rush is probably off (assuming Joao has metal) and you would need to settle a fourth city near one of the two copper resources. If there is Iron, rush him with a 50/50 mix of axes and swords and a few chariots for good measure.
(2) Research the Wheel and Pottery for granaries while going for the Copper due east of Madrid and try an axe rush, knowing that Joao will quickly fill in the gap between you with a city or two, and that your axes may have to take out 4-5 total cities. This may be asking too much for axemen generated from two cities, depending on Joao's troop types. Oddly enough, an axe rush may actually be easier if Joao DOES have metal -- fewer archers to kill ...
(3) REX as in (1), but tech to a religion and convert Joao while refusing open borders. Once you feel secure against a Joao backstab, continue REXing to block Augie as best as possible and gear up for medieval war.
Wonders: Stonehenge may make some sense on this map, since you will be in border wars pretty quickly. Oracle looks quite easy with the marble handy. With the gold handy for research, you may be able to do a Theology slingshot depending on how quickly the Emperor AI gets the Oracle, grabbing a war civic and a religion to boot. (tech path: wheel -- pottery -- writing -- poly -- priesthood -- mono). This could really boost Izzy's war effort -- I don't know how Joao could stop a posse of CR II Swords and Axes ...
My vote is option 1 (block Joao with 2 cities while teching for iron), then going for a Theology slingshot. With Madrid up and running and marble hooked up (and a few timely Inquisitorial whips

) the Oracle would complete very quickly and not significantly delay the war effort.