Hi Domenico,
I think in your case will be easier just to include the store id to the locale resource name, so that you can have different locales for each store. The disadvantage for this will be that there will be no default setting and you will have to add these locale resources for every store. But I think that this was what you needed.
Soin order to achieve this just open the Themes/Motion/Views/Common/Footer.cshtml file and edit it as shown below:
<ul class="footer-menu">
<li class="phone">@T("SevenSpikes.Themes.Motion.Common.Phone" + storeId)</li>
<li class="mobile">@T("SevenSpikes.Themes.Motion.Common.Mobile" + storeId)</li>
<li class="email">@T("SevenSpikes.Themes.Motion.Common.EmailName" + storeId)@T("SevenSpikes.Themes.Motion.Common.EmailAt" + storeId)@T("SevenSpikes.Themes.Motion.Common.EmailDomain" + storeId)</li>
<li class="skype">@T("SevenSpikes.Themes.Motion.Common.Skype" + storeId)</li>
</ul>
So you will then need to go to your Language and add the following resources depending on the store id. They will look like:
SevenSpikes.Themes.Motion.Common.Phone1
SevenSpikes.Themes.Motion.Common.Phone2
......
Please let me know if that will work for you or need any further help or information.