... and if one could then right-click on the selection and have GnuCash-specific options like unreconcile or move transaction (i.e. move this split of all selected transactions to a different account), it would be great!

This feature will also take care of bulk deleting transactions that has also been suggested separately

posted on multiple categroisation as it's essentially mutiple edits

To me trying to learn gnucash this is a must. gnu feels like a one way street for data import, get it perfect first time or you are in trouble. The inability to multiple delete or amend is horrible. You can't even use the keyboard to delete rows.

Many things I like about this so have persevered but this perfect everytime is a killer. I just uploaded some transactions, did all the transfer accounts and then realised I had a mistake in my upload. Quicker to delete the account than the offending rows [as you cannot multiple edit], so deleted the account and said delete all transactions. But gnu doesn't delete the double entry transactions, so now I am left with loads of imbalance rows and loads of rows in the transfer accounts which I can't easily delete. And that's after uploading 4 other accounts perfectly.
So now I am at a loss, manual click and delete or just drop the whole thing and all my setup. OK my mistake but I am a human and humans make mistakes. Can I delete in the base data itself?

non-contiguous selections via e.g. shift, ctl, etc. modifiers would be very useful for selecting accounts for various reports. The only options now are clear all selections, select all, and select children (and the parent account). Plus wired-in pre-selected items (income) seem to be set for e.g. the cash flow report. Flexibility & utility of many reports would be greatly improved if it were possible to select and deselect multiple, disparate accounts to generate these reports. e.g. cash flow into an out of or between equity accounts unrelated to income. When all accounts are selected the report appears to degenerate to almost nothing, with a long list of accounts and a short summary with a few totals equalling zero.

great idea!!!
Specially if we could reconcile multiple at once.

This would become very useful if I could then assign said selected transactions to a category.

Would be nice since it is standard feature everywhere in Windows.

Thanks