Hi!
A-roads over here are quite tough, especially in the countryside.
Having said that, I find most people quite polite and willing to wait for you. That A5 isn't that bad unless there are hedges as well (would get that a lot at the Scottish borders on the A roads) or dips in the road that prevent people from seeing you.
I would NOT ride on the verge as a slight dip, which is common would cause you to correct and send you into the carriageway.
If you want to ride the A5, which you could do if it's mostly like that photo ...
1. Get a Hi-Vis backpack and vest.
2. Ride with the traffic (left side).
3. Ride about 18" / 45cm from the edge of the road.
4. People won't honk and in general will be polite.
5. Try to only ride during the light (not at night) ... lots of pubs make it more dangerous.
I would disregard nearly all of the information above as almost none of those people have lived in the British Isles and often live in Suburban America, which has it's own unique issues (guns and SUVs) that you won't see over here.
Good luck mate