Hi,
1. Web (HTTP/HTML) run time viewer is a naive implementation of browser control which does not support rendering modern applications. It does not indicate anything about the protocol's capability to simulate the right workload against your application assuming you properly handled all dynamic data in your script.
Web(HTTP/HTML) simulate the traffic in the HTTP level. The script is more challenging to create but it is much more scalable.
Bottom line: do not let the Run Time Viewer determine whether or not you use it.
2. If you wish to monitor the Load Generator using performance counters add the Windows Resources graph in Controller's run tab, add the Load Generator machine to be monitored by right clicking the graph and use the context menu to drive this configuration
3. In order to use another Load Generator you need to install the Load Generator sofwtare on that machine and add the Load Generator from the Load Generators window in Controller.
I suggest you go over the introduction section in this online help page: http://lrhelp.saas.hpe.com/en/12.53/help/WebHelp/Content/Controller/c_designing_scenarios_overview.htm
Good Luck!
Shlomi