Hello, I work in IT so maybe I can provide some help.
One problem that you might be experiencing right now is something called "Ghosting" or a lack of 'Rollover', this basically means that the keyboard you are using is not advanced enough to handle more than a few keypresses at the same time, more presses than the max rollover will not be seen and create that weird issue you are getting (where you are probably using 1/2 arrow keys to move/aim, then 1/2 keys to pick your swing type.).
This is more likely to happen on old USB keyboards. But it's been known that very cheap keyboards can experience this problem too, possibly because the creator of the keyboard simply did not account for the keyboard to be used for video games (where 'rollover' is needed the most, since for only typing you are generally only pressing a few keys at the same time). It could also happen if you're using an ordinary office type of keyboard, rather than something designed for gaming.
This is a website where you can test your keyboard, and whether or not it registers multiple key presses at the same time. For example my (way too expensive) mechanical keyboard can register as many keys as you can physically press (N-Key Rollover)
Rollover test: https://drakeirving.github.io/MultiKeyDisplay/If you notice on that app/website that your keypresses are not registering above a certain number, then you might need to get a different keyboard?
NOT that you need a super duper expensive keyboard to play this game, but if this is the problem you are running into, you can look around for gaming branded keyboards, even cheap gaming brand keyboards should have a higher than ordinary rollover to satisfy gamers and their need to press as many buttons as possible!

Cheers,
Martijn
English Wikipedia explanation about Rollover/Ghosting:
https://en.wikipedia.org/wiki/Rollover_(keyboard)#Key_jamming_and_ghosting