> How to I turn on and make page breaks visible at all times while formatting column widths and working in numbers
Short version: you don't.
Each table is intended to be discrete and sized independently, optimized for the screen, not for printing, as such, the concept of a 'page' doesn't really apply.
This is especially true when you consider than when you print your sheet you have the option of scaling the tables from about 25% to 175%, including an automatic "Fit" option that will reduce (or expand) your table to maximize the print area. Since the print options aren't known until you go to print, there's no easy way for Numbers to indicate the print margins or row/column breaks while you're working on the sheet.
By comparison, Excel does have a Page Layout mode which makes some of this easier, but still suffers from changes to the sheet affecting the print area and not being persistent.
> ...to ensure that work will fit on page, and not have one column hang over into next page when printing?
You can do this by using the Scale to: Fit option in the print setup.
> How do I consistently drag a cell with entries to another location, it drags intermittently.
With a cell selected, use a long-press to 'lift' it off the page so you can drag it around.
A simple click-and-drag (whether the cell is already selected or not) will extend the selection to cover the area you drag.
A click (to select) followed by a long-click (click-and-hold) will allow you to drag the current selection