There are more important apps than any you mention.
Firstly, you need a good file explorer. The built in explorer is not very nice and I find it difficult to use. I much prefer explorers that map all memory - like Explorer on your desk top. Resco Explorer 2003 is generally reckoned to be the best, but it has become rather expensive. Very nearly as good but
much cheaper is Advanced Explorer which costs about $2.00.
Secondly, you need a good backup utility. Again the built in backup is not very good.
Much better is Sprite Backup. Among its many advantages is that it compresses backup files to about 50%, it produces self extatacting backup .EXE files which do not need the program to be running to restore and it can be scheduled to do automatic backups either daily (strongly recommended) or weekly. This can be a real life saver. If you buy the Premium Edition you can also backup to your PC and you get two very nice extra programs :
PocketMon - a today screen plug in which monitors the battery charge, main memory, SD card and CF card memory state, and the processor activity (interesting but not all that useful) and :
Space Detective - a useful memory analyser.
If you get these two you probably will not need BatteryPack Pro or SPB Pocket Plus as well, as they do much the same things.
I use both MemMaid and Pocket Mechanic, they do different things. I also use SK Tools which does not have the easy interface of MemMaid but is a lot more powerful.
BTW
Welcome to Aximsite 
You will find both your Axim and the site totally addictive and the site is a mine of useful information and someone will always be able to answer any queriesyou may have. But to avoid asking questions that have been asked many times before, I strongly suggest the you read the Tutorials - especially those by Gigi - and the FAQs. You will find them listed under Resources at the top of all pages.