In answer to your questions:
1. You determine ad expiry when setting up pricing plans, so yes your ads can be set to expire in a pre-determined time frame.
2. This is not a default feature of the theme, and would require customization on your part.
3. The default maximum is 10 images for a listing, so more than that would also require customization. Images are not resized as such, but you can determine max. image sizes.
4. The single ad page has a Google map of location placed in the listing. Otherwise
plugins such as this can allow a map for the homepage.
5. Registration is always free by default, but you can create ad packages (free or paid or both), and also offer featured ads for an extra price. This will place the listing in the featured ads slider.
6. Yes, this is a default feature.
7. You can use social plugins to allow sharing to sites such as FB, Twitter, etc..
Thanks.