It's not a great idea to use different titles for directory submissions as this may be seen as spamming. Also with the directory submission it is advisable that you target niche directories that are in the same line of industry as your website and brand. Good luck in your SEO efforts.
It is very important to use varied anchor text in all the techniques which you are using. In directry submission also you can use all your targeted key phrases in link building. one thing which you should keep in your mind that if you target geo graphically relevent sites in your link building then it will be very useful for your traffic increment.
Google directory submission has to be done via the Open Directory Project. Google gets its data from Open Directory Project, which is also popularly known as DMOZ. If you get listed in DMOZ, you will not have to do separate Google directory submission. You will be able to get listed only in Google directory but you will be automatically listed in other popular directories as well by submitting to DMOZ and to answer your question as per new Google policies Google does not look at multiple titles favorably hence it is best to desist from doing so check out web tools you will find more helpful guides in your quest.