Hi,
If the footage has been converted to 1080 proxy, or something close to it, it should show as 1080 or whatever they did.
You say it shows the RAW resolutions, with that information, I suspect the proxies are not linked, or the use of the proxy option is not activated. You can tell them to create the proxies with the watermark option so you can easily identify if you are working with proxies or the raw footage. I hope this helps. And for seq settings, I believe you should work on a seq that is the same as your export settings. If you are going to deliver it in 1080, you should work in 1080, and if it is going to be delivered in UHD/4K, it should be in that sequence setting. As long as you have proxies close to 1080, you can work flawlessly.
Recently, I worked on a 7K project, and the proxies were created as 7K that was hard to work with, even in proxy mode, and I deleted all proxies and created them all again in a quarter size of 7 K.