On question 1... Not sure what you mean by "show anything shared" exactily. If you mean that it is 45 to 60 seconds before either of the computers (names) or their shared folders/drives shows up in network neighborhood after simply opening network neighborhood, then that is not really a problem. In order to display computers sharing resources and the resources they are sharing windows networking relies on something called a browse master and a browse list. One (only) computer in the network becomes the browse master and maintains the browse list. The process of becoming the browse master is a matter of negotiation between the PCs in the network (there is a hierarchy in terms of flavors of windows and who becomes the browse master). The rules state that the elapsed time it can take to negotiate (or re-negotiate) which PC will be the browse master can be up to about 18 minutes (if memory serves). Generally the time is far less than this (like a couple minutes or less). So if this is what you're talking about then 45 seconds to a minute is not out of line.

However, if you mean it takes 45 seconds to a minute for a list of files or shared drives/folders to appear when you click a computer name or its shared folders/drives in network neighborhood then this may be because one of the PCs is win2k. When an initial display of resources is being done and there is a win2k machine in the mix the win2k machine looks for remote tasks to execute (via the task manager). This is known to create delays. If this later case is what's happening to you then post back, as there is a registry change that can prevent the delay (by stopping win2k from looking for remote tasks to run).

On question 2... Share what ever you need want to. You are not introducing any delays as a product of what or how much you share.