HELP... Need help designing rural water system.

Here are the facts:
I have been on a pond purification system for 25 years. It has a 12 gpm pump that feeds into two 100 gallon "flocculation" tanks. Prior to the tanks I have two chemical pumps that add chlorine and alum into the water line. The water flows through a metered carbon filter prior to distribution. The system worked great .. Water quality was good.

I recently had to add a shallow well system because the pond need to be drained and rebuilt. The pump provides 13+ gpm. Unfortunately, the well water is hard and I need to add a water softener.

Well water analysis:
No bacteria
calcium= 100 mg/l
Magnesium=7 mg/l
Manganese = 2.3 mg/l
TDS= 399
pH= 7.2

The House has 3.5 baths with multi head showers

I would like to be able to use both of the water systems. I plan on installing a Fleck 7000sxt 48,000 WS. I plan on running on the well water until the pond fills (1-2 years). Then use the pond water as my primary source. The well would be used as a backup after large rains when the water retains high levels of sediment. Outside irrigation would remain on the pond system (prior to water system).

Where should I install the water softener ... before or after the carbon filter?
Should I use a larger (2 cu ft) tank?
What ppm should the chlorine be at when on the well system?
Will the chlorine help remove the iron?
How would you design this type of system?