ouR escaPOD mods

For single module 12V battery charging the MC connector approach doesn't offer any advantages. By all means convert over to a two conductor cable (or 3 if you use a grounded extension cord).  You could just cut off the MC connectors, solder in butt splices, and heat shrink, but you would probably get an argument if you were ever to make a warranty claim on that module. 

Be sure to check the gauge of the extension cord if you go that route. A 15A cord is likely to only be 12 gauge or smaller, which is only going to be good for about 25 feet before you lose too much voltage. You'll want at least a 10 gauge cord.  Cut off both ends of the extension cord and either connect one end permanently (to the module or battery) or use dedicated connectors at both ends. Don't use the 120Vac connectors for 12Vdc so no one can get confused and connect the wrong stiff together. And don't try to use the MC's to make connections on a daily basis, they're not meant for that and also require a tool to disconnect which would be a PITA. Please do use a properly sized fuse at the battery end to protect that cord and the module. A 10AWG cord should be good for 30A but most modules are rated for 15A so a 15A fuse is a good choice. 

PWM controllers are fine for a 100 watt 12V module, if you go to one or more 250-350 watt residential/industrial modules those are high voltage so you need an MPPT controller to charge at 12V. Those module are so much cheaper per watt that its worth the extra expense for the MPPT at that point.  

Solar systems are wired in a very wide variety of configurations. We have solar sites with anywhere from one panel to 18 panels, all with different series/parallel configurations. The MC4 connectors are "fairly" standard, and they seem to be the ones on most of the panels we get these days.

I know that kit comes with a controller that can be configured for lithium batteries. is it by any chance an MPPT controller (I assume not, since it would be a "feature")?

I don't use the Zamp connectors but I did make a 50-foot extension cable for my Renogy solar panel.  I used Anderson SB50 connectors:

and this cable:

And these weatherproof boots:

I use Anderson SB50 connectors throughout my RPod solar power system and completely avoid the Zamp wiring.  I connect my solar panel directly to the solar controller in my battery box on the tongue.

you will love this system and wonder why you didn't do it sooner! We have used a Renogy system for 3 years and it keeps our 2 6v Gc batteries charged. It is simple and effective.

We set up the angle  at night before we go to bed. It will start getting direct sun before you even get up in the morning. then adjust the angle before you leave for the days activity and readjust when you get back.  Occasionally, We had to add  blocks under the arms to get the angle we wanted.

good luck

Vann