Pkg files: are they necessary after the installation?

HI

after installing a pkg game or a pgk patch/update, can I delete the pkg files or are they still necessary? I suppose that all the installation files are stored in dev_hdd0\game path  so I suppose that i can delete all the pkg files in order to save space on my hard disk.
Is that correct?

thank you!

Yes, but you may want to preserve them in case you can't dump them again in the future, or your game installation gets corrupted, or you need to reinstall the game to remove extra content, etc

sure, but I have a copy of my RCPS3 emulator installation folder, so I can always have the dev_hdd0\game path  saved, so in case I have to reinstall the emulator, i can simply copy/paste the dev_hdd0\game path folder in order to have all my game automatically installed, is it correct?

but you are right, if i need to reinstall a game, i could need the original pkg file, correct.

I still have 2 questions: 
1) in the game in "folder format", I usually have 2 folder: PS3_GAME (with the game) and PS3_UPDATE, that includes an update file but i think that it is only useful if I need to update the firmware of the ps3. But i can delete it in every game folder because RCPS£ doesn't request it.  Correct?

2) How can I remove a game from my game list? I know that I can right clik and Remove Shaders, PPU, SPU and cache. But i want remove the game from the list. I know that I can hide it. But if i want to add it again in the future, if i don't remember that it is hidden, i could not be able to add it again in the list because it will not appear again (if I don't remember that it is hidden...)

thank you!

Yes, PS3_UPDATE folder is not necessary

If you update the game not will be possible return to previous version because the updated files will be replaced in game folder and not in update folder used in game discs.

thanks!

and what about my 2nd question?

thank you very much