To each their own of course .. my 2 bits .. With some things I'm a bit 'conservative'.
I would recommend a conservative wire sized for at least less than 2% power (and voltage) loss over the longest distance and highest peak power amount for your application .. in this instance leaning on the little bit extra bigger side is a good idea.
I also like using the ultra-flexible type of many strands, as they make maneuvering it much easier.
I would recommend a fuse on both sides of the charger .. the AC in from outlet side , and the DC out to battery side .. some people just use the circuit breaker in their house on that outlet as the AC side.
I would recommend adding a GFI , on the AC input side .. They make these for you, either built into some extension cords , or as a inline device .. I just got one off the shelf at local hardware store .. but something similar to Link
.. that example is rated for 'indoor' so keep that in mind where you use it , or get an 'outdoor' rated one.
I would recommend against connecting or disconnecting while at full power .. a short delay 1-2 seconds on the start of charging can take care of that side , or a switch .. and on the disconnect side, a switch or just don't unplug it while charging at full power .. Some people experience IMA errors if their charger (on the DC side) has components that are detected (ie always plugged in) .. if your charger disconnects the DC side (switch,relay,etc), then you don't get that error .. From the feedback I've read such a AC charger always connected on DC side type error is 'flaky' , doesn't always show up, etc .. seems to vary allot depending on the charger and such .. you could just deal with it (when / if it happens) , find out if the charger you are using has / includes a DC side disconnect while not in use, or just install a DC side disconnect of your own.
I would recommend , a good quality weather proof AC connector .. nickle or such plated connectors to reduce corrosion in the years to come .. and just to double down , I would pick a more 'out of way' from elements location as well .. I installed mine in the rear next to the license plate for that reason.
Bellow 1.5kw charge rates .. a regular extension cord style (NEMA 5-15) connector will be fine .. and conveniently available at your house, when you visit anyone, any camp site with electrical , etc .. If you plan to use soo much so fast that you will also want to stop at EV style charging stations, then you will have to install that type of connector/equipment .. something similar to Link