RE: Application Slow in other countries
Latency is a consequence of the distance the user is away from the home office, more specifically it has to do with how many routers their data is switched through along the way. You have almost no control over this although you might be able to find what route is being taken and try to optimise this with help from the local ISP.
(I heard of a client in Australia who was using the APAC data centre for CRM online and had awful performance. Microsoft were able to help them figure out that all their traffic was going via the US West coast. Talking to their ISP in Australia revealed that their routing plan was "if it is not in Australia, send it to US", since that worked for 90% of their traffic. Changing this so their routers knew that the datacentres were in Singapore, and sending the traffic "left" to Japan instead of "right" to US made a huge difference)
Do some more investigation on the client side to make sure things like caching are working well. Tools like Fiddler will be a big help here. Open a record, close it and re-open it and make sure that the second time retrieves things like html, image files, javascripts, css etc from the cache and does not fetch them again.
Do you have IFD configured, or are the offices connected as a big WAN, so even remote offices are effectively "on the network"? If remote users come in via IFD, some active firewalls (such as TMG) can confuse things so the browser sees the traffic coming from the firewall, not the CRM endpoint it was expecting it from, so it uses the data but won't cache it. You can fix things like this if you know where the problem lies.
You can of course optimise things like views and forms for better performance which benefits everyone, and might be able to get the performance to an acceptable level for the remote offices, even if they don't come up to scratch on latency.