Before putting any deep thought into it, my first thoughts are there wouldn't be any problems really unless you were writing a lot (>10 items a second?) and doing many reads (>50 a second?) in which case I'm guessing you'd rarely get an accurate number of rows in the list, or you may not return all the current rows properly.
I seriously doubt, however, that you'd miss out fields in a bulk write operation, unless you hadn't sanitized the data and had errors, in which case I'm thinking the entire row write operation would be skipped, but I'm not entirely certain.
Programmatically writing to a list is something I don't often give a second though to (got a lot of confidence in how SP writes to SQL), unless the scenario looks like it'll evolve to something resembling an OLTP system.