Best Counter is to hit Italians early. Genoese Crossbow may be hard for Franks to deal with, but until an Italian castle is up, Franks are the stronger civ (with berry bonus, free farming upgrades, cavalry hp bonus, and cheaper castles). Even once a castle is up, it would still take some time to mass Gen-bows. Goths can use huskarls (they do fine even against hand cannons if they can get close, but that’s assuming they can close in), but really would be better off hitting the Italians player early (when Italians are practically a generic civ on land maps). Italian bonuses don’t really start kicking in until mid-late castle age.
Not in my experience. Janissaries and Conqs are pretty good at dealing with condos (so long as they don’t allow the condos to get close, which isn’t a hard thing to do - hit-and-run with Conqs, meat shield with Janissaries).
Hindustanis should have options in the late game. Their hand cannons and bombards have longer range (a significant advantage from UT/Siege Engineers), and Ghulams can deal with any archers (including Gen Bows). Camels likely wouldn’t be a good option due to the gold cost (they may be good against a hussar meat shield, but you’d be trading a gold unit for trash units, which isn’t a winning strategy). Camels would be solid if you were facing knights/Cavaliers, but you likely won’t see those after castle age. If the Italians player isn’t using Gen Bows, then Hussars would be a good option (and would be ok as a meat shield even if there are Gen Bows). And Hindustanis have fully upgraded skirms (which are a good unit against all types of archer units, especially Gen Bows since Gen Bows have -1 range).
I’d also note that Hand Cannons, Gen Bows, and Condos are a triple gold comp, so of course it’s strong. If you’re opponent can field a triple gold-comp, then you’ve given them way too much time to build up, but could win if you survive until they run out of gold. Also, Condos generally get beaten out by another unit in whatever role they play (hussars are better for raiding/meat shield, Cavaliers for a power front-line unit, Champions for an infantry front-line unit). Also, Italian units are practically generic, so feel free to use your own generic units against them.
For Turks against Italians, I think a normal Turk game plan would work just fine. Janissaries are a good unit (even against Condos, since Janissaries don’t rely on bonus damage) and can be created starting in castle age (so you should have a mass of Janissaries before the Italians player can even get Condos out), Hussars are a great meat shield (very spammable - you might lose a lot of them, but you’re only losing food), and their BBC have longer range (a great option against a civ missing siege engineers). So long as you don’t throw away your gold units, Turks should do just fine against the Italian late game.