There are so many booting options!

-Boot game
-Boot game and start
-Install PKG
-Boot (S)ELF

and when you put the whole game folder inside /hdd0 and double click it, a whole new process begins.

What's the 'standard' way of booting the game?

Just double click on the game in the game list. If you have a PKG, Install Pkg installs it. If you need to boot an ELF manually (such as for the tests), Boot ELF is there. Simple.

Doesn't seem complicated to me.. i've ran 3 games so far on rpcs3 and i only use 'install pkg' when i have a pkg file and i use 'boot game and start' when i have a folder with PS3_GAME inside it.