Thank you for feedback.
I initially ditched the default setup in order to problem solve and get my internet working, turned out my ISP (Virgin Media) wouldn't hand out an IP to my DHCP client since it required the Max-DHCP-Message-Size to be 576, as someone else had figured out at this post in this thread:
Also, I enjoy learning and understanding the things I use, and one good way to do so is to start from scratch I guess and build your way up, possibly with some mistakes along the way but that's why I asked here for feedback, just to make sure I haven't made any massive blunders.
Again, thank you for feedback and yes, I will keep those interface lists properly maintained. For now they just contain 4 interfaces for my 4 desktop computers in LAN, and 1 interface in the list for WAN since those are the only 5 ports I have on my Mikrotik device.
//madeupname