Since you are trying to "exploit" the system (call it whatever you like) anyway by changing IP, using various browsers, etc to cast multiple votes why not just run script and be done with it? It's no more or less legitimate than what you are doing now.
Because the system won't allow that, after 2 votes from an IP you are required to enter a captcha phrase to prove you are an actual person and that you as a person are actually voting.
From my perspective that means you are working outside of the system, you are trying to actively circumvent it if you built a script or piece of automation to do the voting for you.
Let's be honest here, the rules for this contest are about as clear as mud, no where does it say 1 vote, per person, per day, even when you hit that 5th vote and you sign in with an account the message you receive is "You have voted the maximum number of times allowed for the next 24 hours"
So my interpretation is, "Ok system, if 5 votes is what you are going to allow for a single device/ip, then 5 votes is what I'm going to do"
I'm not using a Proxy or VPN to mask my IP to circumvent the system. I'm not circumventing the system by creating a script that votes for me. I'm working within the confines of what the system will allow and until someone else tells me otherwise that is all I have to go on in terms of rules for this contest.
and all I'm asking the people that vote me to do is work within the confines of the system.