1000mAh means that you can take 100mA for 10h. When you really need extremely high current, consider a maintainance-free Pb accu. Note that Pb's can start cars or pull 4WDs out of the dirt. I have seen cave divers carrying huge Pb accu tanks for their lights. Whether you call it memory effect or prefer a more sophisticated explanation, the nuisance is the same.
Some chargers discharge the battery prior to charging it.
The memory effect occurs only with NiCad's. NiMH batteries have no memory effect. DON'T leave the cells on trickle charge for long times DO protect the cells from high temperature both in charging and storage. DON'T overcharge the cells. Use a good charging technique.