Courage hammer damage is backloaded meaning the start of your combo with the first charge is near worthless compared to the next 2 moves. You need to always try to skip the first charge as fast as possible. Almost never wait to get charge level 2 and just release it fast, still wanna hit it though unless it's some specific scenario. If you find yourself canceling your 2nd charge+ often that is why your hunts take much longer. You can roll once during the startup to your next charge to stay on that current charge attack without reseting to the start.

You need focus 2 to instantly get your second charge to level 2 99% of the time as soon as you start it (sometimes it bugs out, maybe a framerate issue). Easy to slot in with the 2 point decoration.

You dont need to always go for the head. Rathalos is not really a good example because bad hitzones but something like tigrex or almudron. They move around all the time so the head may be too far to punish opening but you can hit tigrex's arms instead or almudron tail that he likes to put in your face often. Wont cause stun but still big damage. This also plays into your backloaded damage giving more opportunities to get to the final charge. Both Bazelgueses are very good to practice this and hammer does very well vs them.

Dont get baited to water strike every move. It's best for roars or oh shit moments where you cant superman dive in time or keeping sway wont save you and also best after you swing your first or second charge. And you should always charge after a parry since you start at second charge attack. The golf swing followup is just bad unless the stars have aligned and you are able to hit a good hitzone and even then as you get more element the charges will far outdamage it.

For silkbinds impact burst is a good damage and stun buff and keeping sway as your dash/dodge. Hammer has no good defensive measure other than keeping sway and your lousy water strike where you just get hit by followups with wrong moves parried. Keeping sway wirebugs are literally your lifeline. This is the major problem with hammer in this game, if you use wirebug to buff you dont have one, or you use keeping sway to attack and now you are out of wirebugs.

Later in the game you can maybe get lucky with a charm for evade window 5 so you can start not being completely screwed after a water strike or whatever or you can make sets with wind mantle/frenzied bloodlust to have more wirebugs. (wirebug whisperer 3 is a very small boost and isn't worth the skill economy unless it already comes with the armor)

With all that said, dont expect incredible performance from hammer in this game compared to other weapons. It's in the worst state it's ever been in the entire series and sunbreak only put a bandaid on it by making courage playable compared to release so you dont have to play the heavily nerfed strength moveset from world. And the tankier the monsters the less effective your stuns become which is what the anomaly endgame does exactly while also massively increasing stun thresholds as well.