Urgent! External linking, who bears the load?

Ok, so I have the task of creating animated banners for our curatives on a require bases. Now the company we frequently advertise with has some very strict limitations they require all files saved back for flash 6 and banner file sizes need to be less than 30kb.

While one of the smallest file sizes I have had to work with to date its made no easier by our team of creatives none of which have a background in digital using as many images as possible to make up their banners. (I have already given them tips and techniques)

Of course the sacrifice is high file size, poor image quality, or getting rid of elements…or is it?

Would external linking to my objects work? Now my question is (finally) when I externally link to various images on another server where does that place the load? Would the site that we advertise on be inflicted these load times as well as the user because in which case I imagine they would notice the load and be most unimpressed (after all they have a minuscule size allotment) or would they burdon none of the cost of my external linking and hence be none the wiser allowing me to sneak though a nice small 30kb banner loaded with externally linked imagery?

I would love some feedback on this issue as we are having a meeting tomorrow to discuss our options. I have also heard there are some security issues with this idea also… are there possibly other things I also need to consider?

Thanks for your time.

I think I may have answered my own question. I cant externally link to objects or other files on another server than the one the flash resides on without creating a policys files. And of course we could never get an advertiser to place this in there root directory. Unless anyone has any other suggestion?

I been doing banners for a while, and you rarely ever externally load a image or resource, actually I 've neever seen it done at all. I ain’t that experienced in the banner business, I only been doing it for a year.
But from all the banners I see, everything is in the fla.
Usually to get the banner to the size restrictions, you haveto lower image quality. Thats what always happens.
Thats why you see so many banners online with sh!tty images. Not because the design studio wants it to look this way, but thats the only way they could meet the ridiculous size requirements. 30k for a banner is brutal, your banner is going to look like crap unless its all text and gradients.