KAZESUI'S PROFILE

common events are events that are common for every map... it's about as simple as that.
if you paste the event into a common event, put it on autostart when switch CELL is on, it should perform the exact same task.

the conversation event you could just paste in an leave as "call" meaning it will only activate when you call it.

If you're unsure how something works and worry about messing stuff up, make a test project and try stuff out with simple versions of what you're trying to do

judging by the date format showed in each post, and everywhere else on this forum, one could make the guess that it's rather using the silly american style MM-DD-YYYY

have you unchecked the keys in the key inputting process irrelevant to the event you're working on?
if not then that "input of spin" event of yours will keep triggering either the spin or stop spin move event, which overwrites any other move event which might have been executed before that, since the rpg maker only allows for 1 active move event per event at any time.

In case you have the "wait until key is pressed" this would also be the case. I guess you ought to add another branch for the input for spin to check whether it's already spinning or if it's not, and only have it process the "stop spin" if the switch "spin" is on.

I think this topic belongs in the "help & request" forum though

that's because the movement of the hero through move events commands won't trigger such events, be it hero touch or collision. (edit: if event is same layer as hero for collision)

For picking up items below the hero, it shouldn't be too time consuming using coordinates though. Just a matter of storing the coordinates of the hero in a variable and then use "get event ID" on those coordinates, and if the event ID equals the one of the item, you make it do whatever the item is supposed to do.

The easiest way to do this would be to teleport to an outside map. You always try to make some deal with kentona where you'd submit an extra map which serves only for this purpose which is to be added right after you main map, which would allow you to toggle between the maps by adding/subtracting one to the map ID variable.

pretty much the only alternative I can think of to that of manually placing all the events back with the "change event location" function, and couldn't hurt to ask whether it would be too much a hassle