That's pretty much it. The protections are in all vertical modes except VS which has none. However, there are none on the flap lever. If you select flaps 20 knots above limiting speed, they will move and you will have an overspeed. As with the gear. When slowing for configuring, I don't remeber using the FMC speeds. I alwats remember using selected speeds as you had far more control.
The Boeings will start a descent if Top of Descent is reached and a lower MCP altitude is selected. The FBW Airbus models will not, you have to select a lower alt, then push (for managed) or pull (for selected) the alt knob to make the thing go down. It only took me about twenty flights and about nineteen screaming dives to get that right when I started flying the thing!
A 'Route Full' message on a 747 is unlikely, it has much more memory. It depends on the company SOPs as to whether the approach is loaded at the planning stage. My company did as a matter of rule, because it gave you a better idea of the fule situation in the cruise. Mind you, a destination approach loaded at Heathrow may not be the same as the one on arrival in Hong Kong 13 hours later!