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TEXT/LONGTEXT is quite undesirable -- and in v5.0+, VARCHAR can be 65K, so you rarely need TEXT (VARCHAR was only <=255 in v4.1 and below). These very large fields have implications for sorting/group by operations, data seeks, etc. They should be avoided if possible -- and if not, they should be in their own table, ideally.
BIGINT it *really* big... INT gives you 4 billion numbers (8 billion if it's UNSIGNED)... takes up half the space, which can be very important for indexing too!
You can use TIMESTAMP for created/modified, but it's a bit tricky, there are time zone issues, max date = 2037, etc., etc., so be warned. I prefer DATETIME, even though it's a few extra bytes.
So, in a nutshell, drop the BIGINTs, use VARCHARs with reasonable lengths (be generous, but not an order of magnitude), stay away from keywords like "date", and don't use [LONG]TEXT fields. Obviously, indexing some other fields will be necessary, too.