If I fly a 190, its always the 190A8 with the "big gun" load-out of four 20mm and 13mm nose guns. I WEP from the runway to 15k, then keep climbing on normal power to 20k. From there, I either engage enemy planes in an HO where my superior firepower usually wins the battle of lethality (except against N1K2s, Typhoons, Me-110s, and Mosquitos with their standard guns or the 109 with the 30mm option or the Yak 9T with its cannon) or I drop down low and behind an unsuspecting target and catch them in their blind spot. P-47s are about equal in an HO so be sure you fire early and often when going up against them.
When I drop down low and behind a target, if they spot me and start maneuvering, I just let them go. The 190A8 has the worst turning ability of all of the fighters and bleeds energy very quickly which makes extending from the fight difficult if you are engaged by multiple bandits.
I call the A8 the ultimate plane for new pilots because, quite frankly, you don't want to try the fancy ACM stuff in it. In the A8, if you can't get the direct 12 o'clock or 6 o'clock shots, you can still shoot a plane down in a wild-assed snap shot fairly easily. Those 4 cannons and 2 machine guns throw a lot of lead in a wide area and you can really spray down anything in the zone between your wingtips. No fancy stickwork necessary.
The A8 is great for working through a baitball of enemy planes. You just blow through the cluster and shoot at anything in front of you, then pull up into a gentle climb (with WEP to keep your speed) and then do a gentle turn around and make another run through the enemy beehive.
And the A8 will award you with a lot of perk points - certainly moreso than the Spitfire, N1K2, P-51, and LA-7.
As for defense, there is none. Either you can outrun your opponent or you can't. You certainly won't beat them in a turnfight. Shoot and get out as quickly as possible.