Can we establish security on certain columns in the list? Something like Views in RDBMS; so that we create such separate “views” lists and set required securities.

Inventory list; have columns for issue date and issued by; we want; only certain users can update this information.

Can we establish constraints when data is being entered in the list?

We have an inventory table; and another lists representing items with bad status; and items with good status; we want if an item is added into bad-items list; it may not be entered into good-items list.

Examples are just imaginary; there may be workarounds for the examples quoted above; but I need to know if the above two things are possible in Sharepoint lists?