It is currently possible for players to break item frames on the spawn platform of maps. Modifying the spawn platform is something that shouldn't be allowed. Also players could take items from those item frames and take them into the map.

Also players could take items from those item frames and take them into the map.

Have you tested this? It shouldn't be possible for players to bring items from the spawn platform into lanes.

Autoref clears your inventory, but you can still drop items on their own through the spawn troughs and they won't get destroyed. I have tested this. I'll create a separate issue for it.