Elgg 3 creates the tables of its database with the correct collation on new installs. Also, Elgg deals with migrating the database on its own when upgrading from 2.3 to 3. So, you wouldn't have to do anything. I also don't think you would have to add anything about charset in .htaccess. I think Elgg adds it to the page header on its own.

@iionly, thanks for the feedback. When Elgg 3 stable release is available, I will go for an upgrade, and as suggested by you migration would be automatic. 

@rivervanrain,

Thanks for both the links, which answers my Q1. Thank you sir. Thanks for your help. Appreciated.

Have a look at http://learn.elgg.org/en/stable/appendix/faqs.html?highlight=disable#white-page-wsod

I haven't tested if this still works in Elgg 3

Or you can use the commandline to disable plugins

http://learn.elgg.org/en/3.0/intro/elgg-cli.html#available-commands

Well thanks for the link, i was able to isolate it to Elggbook_pro.

the CLI is amazing..

It looks like the method with creating the file mod/disabled still works on Elgg 3 to prevent the plugins from getting loaded. Though it looks like some cached views (like custom_index index page) still get served as long as the cache isn't flushed.

That's not how Flash works. FLV/SWF are just file formats and these files needs to be embedded in a page properly for the client to be able to deal with them (i.e. playing the files instead of just downloading the files). And the Flash plugin needs to be installed in the client browser or it doesn't work anyway.

ffmpeg is just a tool to decode/encode multimedia streams/files (e.g. change formats, resolution, codecs etc.). It does not play video or audio files itself.

For Elgg you would create a plugin that would embed the flv/swf files within a page correctly (files either provided by also offering some upload functionality or just be able to deal with files already part of the plugin). For example the izap Videos plugin (my fork) used the flv format and a player to be able to play the videos uploaded by the users (all files were converted to flv using ffmpeg if not already in this format). Swf is something different (used rather for some game stuff but not videos).

But Flash is almost dead already and soon will be totally dead for sure (it is no longer supported on mobile devices and in 2020 at the latest it won't get supported by Adobe anymore - maybe even sooner by any browser). I would advice to not start using it (and if you already use it try to get rid of it). For videos you can use the mp4 format which allows video playback in any modern browser without the need of any browser plugin with the html5 video tag. The recent versions of my iZAP Videos plugin fork supports html5 videos and no longer requires Flash. Instead of swf and Flash games I would suggest to look for html5 games instead (still some work necessary on the Elgg site to implement it in a plugin or if the html5 game comes from some other site to serve it via an iframe).

@iionly, Thanks for in depth and well encapsulated explanation. As suggested by you, I will look for  html5 games. Appreciated.