FF Addon utilisation

I run win7 and FF. At the moment I have about 10-12 extensions, some of them are the same type as I want to trial and compare a few of them.

A problem I've always had with extensions is that I have not been able to use more than 3 or 4 at any one time as the others just to not appear anywhere for me see them and use them.

I try to place them into a second row beneath the search box but I cant 'find' them to place them in this location. Those I use are the ones that magically appear either in the search box line or in the window that appears when I open the 'Customise' box.

I've even go into the 'extensions' area using a "manage your addons' icon, one that looks like a jigsaw pussle piece, and gone into the each extension looking for a something to tick something like a 'activate' or 'use' box to try and get it to display so I can use it but no good.

Is this just the way FF works or is there a way of turning on or making extensions active that I dont know about.

thanks to all.

Not all add-ons will show up on the bar . They are not designed for that. Out of 20 or so I use , 5 show up.If they are listed and enabled , they are most likely working .
Possible answer.