If the images won't upload at all, there is probably a technical reason why. Without knowing anything about your system settings and browser being used, it's hard to say. Please file a customer support case so that we can look into that for you. If you had tried the beta version of the uploader and are now trying to use the full version, you may just need to clear your browser's cache.
You do not need to resize your images prior to uploading with the new uploader. We do resize images before uploading automatically to make uploading faster.
The option to let users choose what maximum size they save the images as in their account has been been around for several years now, we just added it to a more visible location so users are aware of this feature.
As we've mentioned, we will not be able to support the old Aurigma version past April due to Chrome ending support for Java. However, you can still access it via this link http://www.auctiva.com/Aurigma/8.0.49/Default.aspx until then.
Hope this info helps!