Rather than be dismissive, as some other posts have been, I'll try to help.
The first point is to emphasise it would be incredibly difficult to join a motorway but not impossible. I wouldn't worry about this. Saying that only yesterday as I joined the M65 (a local motorway) near Preston a car came towards going the wrong way on the motorway! Scary!
As for general navigation your cue sheet suggests you've used mapping software of some form. Can you put this on a GPS unit? It will be the simplest solution.
I once rode from home to Bordeaux without using a GPS unit. I carried maps. Each evening I would study the next day's route, noted the road numbers and village names and approximate distance between each village in a small note book (about 2" x 2"). I carried the notebook in my jersey pocket and simply referred to it when needed.
It sounds to me as though your cue sheets offer every minute detail, possibly the routing is diverting on to very quiet or traffic free lanes. I would advise against carrying reams of paper. If you do get lost, miss a turn it will quickly become apparent and quick reference to a map will correct you.
Going back to cycle lanes. In the UK we have a huge range of cycle paths varying from very good to utterly disastrous. My buddies and I do use them if it suits us. We would ignore the example you posted.
The good ones will be fairly obvious. Broadly speaking the decent ones will be signed on the lines of these below. The signage is generally good but can be difficult to spot. I rode the Pennine Cycleway, 350 miles, using only the signage. I had maps as backup but hardly used them, if at all.
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