The Only Complete Twitter Cards Plugin in WordPress. Supports Product Card & Summary Card with Large Image. Advance Automated Settings.
No, just activate the plugin and follow the steps.
Images larger than 120x120px will be resized and cropped square based on longest dimension. Images smaller than 60x60px will not be shown. (From Twitter Cards guideline page).
Yes, check this page for detail guide.
Use plugin support button in WordPress.org extended listing.
More FAQs - here