Those are just three of the big ticket ones. So... music? If i can get away with giving somebody a % cut for the end product that would be ideal but most music people are like us, striving to get by and make it paycheck by paycheck. They need that money just as much as we need the money to make our game.
Just as you have expensive software and such to help make your game, many audio pros (or folks wanting to become pros) spend hundreds or thousands of dollars on their set ups to be able to make music. So offering just the chance (i.e. risk) of making a percentage can drive off folks who make a living doing this line of work. Or even folks who do this on the side but need to make X amount of cash to offset the debts they took on to set up their rigs. If you can only offer profit sharing then might I suggest you at least allow the composer to retain all rights to the music? This way the person can re-use and resell the music in other situations and potentially make another buck or two. Either from other projects or royalty-free libraries, etc.
It could even be a hybrid situation - composer grants temporary exclusive rights for X amount of time and then you can either purchase the full rights (buy out) once the project has generated enough profit or the rights transfer back to the composer. Or if the game performs poorly or isn't finished, there's still options for the composer, etc.
I've done this several times with projects and it's a good compromise. What doesn't seem fair or appropriate to me, as a fellow composer, is only offering profit shares in exchange for exclusive use of the music. Because in that case there's a risk that the composer will end up not making any money and not even owning the music. And I'm probably somewhat biased because when starting out, I worked on a ton of profit sharing games and earned exactly nothing. Also none of those games were ever completed. So it left me a bit raw in that regard.
Just something to consider (for either this or future cases)!