The charger is operated by selecting a charge mode and lipo has several diff modes - lipo balance mode, lipo charge mode (no balancing), lipo fast charge, lipo sorage mode and lipo discharge mode.

The charger only does the mode you select. You will not need or use discharge mode - so 2amp is ok since you're not going to use it. Discharge in your RC, its much faster that what you can do in the charger - the charger is discharge watts limited and it'll take literally hours and hours.

Always use lipo balance - that is the safest way to charge. Lipo FAST charge is for racing where time is limited and you're willing to take about a 90% charge as a full charge, you prob won't be using it either. Lipo storage is one mode you will be using. Lipo lasts longest when it is not left fully charged for any longer than necessary. When I run, I usually come home and storage charge mine so they will be at storage voltage until I get ready to use them again. I charge them for running right before I go out to run that way I minimize the time they spend at full voltage.

Chargers are more effective if they have to charge a lipo to get back to the storage voltage thats usually 3.7-3.8v/cell. You can increase the rate a littel, I use 0.1 to 0.5amps depending on the size of the lipos, bigger mah I use a little higher rate. You want a slow charge to storage since you're interested in storing at what's called the resting voltage.