Many thanks. I think I got the gist (grist??) of the rest of it.
I 've tended to do a 10 min ferulic acid rest at around 45C for my last few Weizen beers, but I'm not convinced it's of great benefit, and possibly makes the beer more "clovey" than I would like. Maybe I'll try the acidulated malt and single step mash, though I'll need to change my water treatment, too.
Agreed about the type of hops: I generally aim for around 13 IBUs, and I suspect the various calculators will make little difference at this low hopping rate. Anything between 11 and 16 should be ok IMO. I've used Tettnang & Hallertauer Mittelfrüh in the past: Hersbrücker would be an interesting change. I saw a recipe this week that suggested using Herkules, which I'd like to try, but they seem difficult to get hold of in the UK right now.