1. I turn off online DRC. I find it more bothersome than useful, but YMMV.
2. Consider shelving polygons while routing (T, G, H or select polys, right-click, Polygon Actions, Shelve Selected).
3. You can enable automatic repour (T, P; PCB Editor/General, Repour after Modification), but beware, it's quite slow on large polys with lots of holes. You should consider shelving those.
Tim