Slow Dashboard

Hello,

I have a little problem with my website and would like to know if someone could give me an advice.

Since I upgraded to 3.9.1 my site was really slow to load. Just before that it was fine, so I’m pretty sure the 3.9.1 version slowed my site down.

I installed W3 Total cache and noticed a good improvement (but still a bit slow).
However since I installed W3 Total cache, my Dashboard is now extremly slow! The Dashboard was fine just before, so I’m pretty sure W3 Total cache slowed my Dashboard down. Pages need ages to load.

I don’t really want to deactivate W3 Total cache as I need it for the website, so would you be able to tell me how to fix the problem?

Is there a setting in that plugin which could fix my Dashboard?
Did someone already reported that issue with that plugin?
Is there an other plugin to speed up a Dashboard?
I was also thinking about “WP Smush it” but I didn’t have time to look into it yet.

Other question:
This is the list of my plugins activated :
Askimet
BackUpwordpress
Contact form 7
English WordPress Admin
Google Analyticator
Limit Login attempt
MailPoet Newsletter
Really Simple Captcha
Tiny MCE
W3 Total Cache
Wordpress SEO (Yoast)
WP Google Font
WPML Multinlingual CMS
WPML String Translation

I’ll probably add an extra one to secure my site against piracy in the next days.
Is it too many? Would you recommand me to deactivate some, like Tiny MCE, Really Simple Captcha or Mail Poet, and to activate them only when I use them in my Dashboard?

Thanks for your help and yor time.

PS: the website url is:
http://www.eurominds-linguistics.com

[ No bumping please. ]