Glad the videos were of a help.
As for config the vps, thats going to be some testing on your end. Start at like 10 threads with 90 second timeout and then keep turning up the threads until success tapers off. Thats the accurate way. If you want to shoot from the hip, go for 100 threads on a 60 second timeout. Your biggest limitation is that 1GB of RAM (and maybe the processor). But its likley that windows is eating 300-500MB of that 1000MB RAM so you are left with about 500 for scrapebox to use. So you can't work with super large lists. I would "guesstimate" that you shouldn't try to post to lists larger then 100-200K. Id go with 100K to be safe, else you could get out of memory errors and scrapebox crashes. Using the crash dump logger is going to be a good idea for you. Video I have on that here:
http://youtu.be/yzWukXbwGcY
Using public proxies for commenting will reduce your success, but you can always repost failed a few times.
The 403 on the private proxies means that either you don't have them setup right:
IP

ORT:USER

ASS
or
IP

ORT (if they are IP authenticated rather then user/pass)
OR
it could mean that you have too many simultaneous connections. Most all proxy providers have a max simultaneous connection limit, "a lot" of providers set this at 100, hence my 100 connections suggestion above. But you would want to ask your provider, as I have seen some that are absolutely ridicoulous at only 10 connections, right here selling on BHW and a very few with no connection limit. Most is 100 per server. "per server" is very hard to define. So just ask your provider what the limit is.
As for setting up the email, its under options >> setup email notification. Then just plug in your mail server details, check off the options you want to receive emails for and check off to enable notifications.
Here are the instructions:
http://www.scrapebox.com/scrapebox-license-transfer
You can do it for free 1 time per month.