Create link server - it helps there.

Are both servers 2005 + ? Except didnt work in SQL Server 2000.

Just iterate on all host and make dynamic connection for each host you have using Script Task Editor.

ie.

Dts.Connections["DBConnection"].ConnectionString = "Data Source=" + Dts.Variables["YourHostnameVariable"].Value + ";Provider=SQLNCLI10.1;Integrated Security=SSPI;Auto Translate=False;";

Then just use DBConnection...

Read about XML Configuration files. It makes the job when moving SSIS from dev to prod.

Add Script Task and change file permissions before and after reading/writting it.

I do not know what you mean exactly but if you mean SSAS properties you can use DMV views.

Use sql script task to generate variable and then use it like a filename.