point me in the right direction if im in the wrong place here

firstly i have jailbrake 4.0.1

wanting help on using iphonebrowser to be able to manually free up space on the iphone without deleting things that should not be removed and the locations of which to find things as i prefer the explorer style way of looking around the phone to itunes.
also if there is some kind of windows explorer "type" app that would let me view the phone in a similar way as to not need a pc to manage files

and info on for example where to drop video/movie/music files onto the phone and what formats are supported,and to be able to drop file types direct to use as ringtones would be great

but the main thing to start with is being able to manage files to create more space when for example there a hidden files i may not need, partial downloads and so on.

iv managed to be able to back any ********** download files easy enough with iphonebrowser on pc

but have noticed under :root/user/aplications is where the app are installed
and have allso noticed under :root/var/mobile/aplications there are the same files
am i right in thinking i need both sets? or can i delete one to make more space?

also i found a stray game Asphalt5.ipa under
i deleted that as i guess the first install didnt work and it gave me more space with no problems

are there any more other folders of these types i can remove junk from?

allso is it safe to delete files in ;root/library/logs/crashreporter
as that could free up a small amonunt of space