I am working on [LearnBiz Simulations](http://www.learnbizsimulations.com/), a self-funded start-up which makes simulations for the domain of management education.

(a) Our website is currently catering to about 16k people. Currently, size of database is 30 mb with a total of about 90 tables and each table may have anywhere between 5 to 50 columns. All our tables in the database, repeatedly have new rows of insertions, deletions or updations. But no columns are ever added. Does it create any issues with employing indexing techniques? There were a couple of other forums and videos which suggests that even inserting or deleting a row will render indexing useless!

(b) The maximum work on our website is mysql queries with some processing of lines of code ranging between 200-800 lines. Almost 95%+ of our queries have multiple equality where clause, to pin-point the row required. If I understand correctly, then employing indexing will help us speed up the process multiple times faster?

(c) There are some simulations which process data of many participants every minute. For such simulations, currently we are not able to cater even 50 participants at a time. Would employing indexing help such simulations bear many more users?

(d) The server we have currently is a VDS with GoDaddy (costs around $400 annually). To make our website faster, would it make sense for us to shift to a DDS (costing around $3000 annually) or get something like TokuDB? Is there a way to judge user capacity of current system, i.e. server + database + coding?