I am amazed at the amount of knowledge you have acquired by doing it yourself! That's also my main motivation for building my own stuff (+ it's really fun when you take your time).
I built a small balcony garden off a few pine planks. Many mistakes were made along the way, some were corrected (how do you cut in straight lines with a jigsaw ? Use a maconnery ruler and a few clips), some were compensated by the overall overbuild. It took me a few months but I always expected it to take more time and money than buying it from Amazon. One nice thing is that it matches perfectly the width of the balcony! With this small success and many more, I will - maybe - have enough knowledge to build my own cabin in 40 years.
Hey that sounds awesome! Don't know what a maconnery ruler is, but I feel your pain about straight cuts with a jigsaw. Lots of clamping on a chunk of spare wood as a "guide" and even when you do that, if you try to push the saw through the wood like it always warps on the free end, so you have to just be patient and do thick boards slowly -- which means that you need another chunk of spare wood for the saw to sit on as you are starting out the cut. (Or only cut through thin wood so that you never notice the warp.) I think you could make a case that the most versatile and powerful tool any woodworker has at her disposal is her clamps.
I built a small balcony garden off a few pine planks. Many mistakes were made along the way, some were corrected (how do you cut in straight lines with a jigsaw ? Use a maconnery ruler and a few clips), some were compensated by the overall overbuild. It took me a few months but I always expected it to take more time and money than buying it from Amazon. One nice thing is that it matches perfectly the width of the balcony! With this small success and many more, I will - maybe - have enough knowledge to build my own cabin in 40 years.