Help with data management

[Prever77]

Hi. Long story short.

I made year or two ago my own package of scripts for role play server, which i never started. 3 months ago i decided to rewrite everything. As i looked at it and said "what a mess. Who wrote this?" meanwhile i've gained experience in C and good habits, so choice to rewrite everything was obvious for me at that moment.

So i did basic optimisation. What can be stored and should be in bools is now stored in bools. not 1 and 20s lol. etc etc

But for now i hitted the wall. Which is named "to buffer. Or not to". By that i mean. My scripts are connected to outside database as built in database is.. well not so fast and secure. And i didn't used to do that mechanism in original code. But i think it's rational to store very often pulled data from database localy on server memory. And update tables in parts to database like every 30seconds. Also i want to use buffer data and database to validate what comes from client side. Im storing vehicles on map, their custom data etc etc.

And here's my main questions.

1.is it worth of effiord to make buffer if i plan 80-200 players on my server.

2.is validating client data with buffer and database worth concept

3.what are your coding advices for me?. Im Asking experienced ones that ruled servers with large player base. 

--[[btw i know that if server has 3 players buffer is not needed. Thanks, awesome advice.--]]