Cut and Paste cells - update formula in other cells

Hi all, I've recently switched from using spreadsheets by Google online to numbers by Apple in iCloud (trying to get rid of all things Google) and I've noticed that it's not really as good and there's a couple of things that don't seem to work so well. Perhaps I'm just missing something so if anyone can help me I would really appreciate it.

Firstly, if I copy and paste a bunch of cells with numbers in them, any other cells that reference them continue to reference the old cells before they were moved. In spreadsheets it would update the references. Imagine you have a list of numbers and a sum total at the bottom - if I copy and paste or cut and paste half of them to move to a different column the total won't be right anymore. I hope this makes sense, it's hard to explain!

Second, if I have multiple columns (say A-F) with 10 populated rows in each but wish to reduce the cells in one column (C for example), I can't see a way to highlight the top rows it in just that column and simply shift the remaining cells in that column up - is that possible? I can only see the option to remove the entire row which would affect all columns.

Thanks for reading and hopefully someone can help me out.

Michael