How to use Filestore in API in Agiletoolkit?

i am working on an urgent project which involves implmentation of filestore of Agiletoolkit

i went through the doc here => http://agiletoolkit.org/doc/filestore

$f=$p->add('Form');
$c=$p->add('Controller_Filestore_File');
$c->setActualFields(array('id','filestore_type_id','filestore_volume_id','filename','filesize'));
$f->addField('upload','upload')->setController($c);
$p->add('H4')->set('Previously Uploaded Files');
$g=$p->add('MVCGrid')->setController($c);
$g->dq->limit(5)->order('id desc');

there is this example there

Questions:

Q1. I know i don't need to use MVCGrid addon here but why is it mentioend in this example? (its confusing me )

Q2. Filestore is a controller i get that .. so if i want it on multiple pages, do i add it in the API ?

Q3. If suppose i add something like that in api can i use it in all pages ? if yes then how ? $this->api-> WHAT ?

There was a small bug in filestore which is fixed now. So it should work fine. It was a bug in sql queries that were imported.