**** you **** and your ****ing **** ****. ***** **!
But seriously…
1) Yes, I would suggest crimping the connecter first, then solder the crimped connection, then heat-shrink over it….I personally DO NOT solder directly to the speaker leads because it makes it a ***** to remove the speaker if needed and sometimes (if done incorrectly) the heat can damage the speaker voiding any warranty.
2) Yes, just strip the wire to the required length and secure it into the terminals…try to be as exact as you can with this step (and other wire connections to the amp) stray/frayed wires can touch each other especially with todays small footprint amps where the connections are very close together.
3) The # of RCA's will be determined by the # of outputs from your source unit or DSP…if you head unit has front/rear/sub…and your amp will take 3 sets of inputs…then you're all set. Most multi-channel amps will allow for a single set of RCA's up to 3 sets to be used as input signal.