I guess I will now take another stab at this post & try to elaborate more on the first of the OPs three part question."Would it be possible to just surf from couch to couch?" I guess it is possible to surf from couch to couch (but it wont last forever if one cares about their reputation).
CS may be free but not really for freeloaders. There is an underlying expectation to use the surf for a cultural exchange, not really as just a way to save money by renting a hotel/motel/hostel. By eliminating the financial transaction many more opportunities to participate & exist in actual community present themselves. Often it is expected to do something nice for your host (making a piece of art, writing a poem, giving a small gift, preparing a meal or treating the host to a restaurant, or helping by doing some simple household chores. This common courtesy is more symbolic than anything but it shows appreciation. I have given books to hosts (often acquired at a free book pile , yardsale or used book store, repaired bicycles, given concert tix & vip passes of shows or fests I am working, done the dishes or purchased some simple every day ingredients like milk, bread, eggs & or coffee. I am usually flat broke but there is always something nice I can do to show that I am grateful.
I recently heard a story from a host where a young kid (20 years old) from Iowa came to the big apple & requested to stay for 1 day; he had no plans, no money & kept asking to stay just another few nights until he could line something up. This went on for 9 days. The host is very active on CS & was 80 years old & luckily for that kid was understanding of his bleak situation. He was just a dumb, lost & misguided kid that naively thought he will move out to NYC, find a job; get a place to stay etc & it will be just like in the movies. He also dreamed of hitchhiking back home to Iowa but also clueless as to the how and where to start.
So this story from the host where i was surfing brought up the topic of hitchhiking. I did not overstay my welcome & surfed for the 3 days that I requested but there was an uncertainty in the back of the hosts mind due to an unpleasant experience with the other kid (that he mistakenly thought was a Traveler since he mentioned hitchhiking). I could sense an skeptical undertone in & around the topic of my hitching & was uncomfortable that he thought that by me traveling via hitching that he was gonna have to endure a repeat experience. I do now have all positive references on CS and know exactly how to travel without money via hitching,hopping trains, rideshares & megabus. I also know top not take advantage of peoples generosity & or overstay my welcome. I guess this is to all of us in the traveling community; we are a small subculture that most of mainstream society has forgot about. As someone who has been around awhile it is my responsibility to leave the nontraveling world with a positive experience in dealing with us travelers. What I do & how I act could have negative consequences on others down the road. In this case I did have to defend how I travel but also defend fellow travelers. It would have been easy for the host to decide to only host foreign tourists who arrive by airplane, with the understanding that their travel itinerary is most likely rock solid & that they possess the financial means to rent a room or amend their transportation if anything happened. Most frequent couchsurfers know how important there online image is to prospective hosts & never want to tarnish it. I had absolutely no money & or definitive travel plans besides what time I would head out. I was given coffee & a bowl of cereal every morning that I welcomed as both the additional charity of my host. This also gave us the opportunity to get to know each other while sharing these simple meals. It would have been wrong of me to help myself to all of his groceries & or avoid these 5-10 minute exchanges of small talk to get acquainted with each other. After all I am a total stranger sleeping on his couch.
Luckily I was able to salvage this hosts uncertain image of the collective world of transient travelers. I am clear & open on my way of life & how I travel on CS and elsewhere online. Part of couchsurfing is the cultural exchange; with many people wrongly assume that local & or regional surfers have little to offer & refuse to host them. I try to add value to every situation that I am in.
The only way I can think of achieving long term multiple surfs in one place is to constantly be lying & changing your profile or having multiple profiles to keep a few steps ahead. That sounds like a lot of work & deception & doubtful that anyone will last too long undetected on
www.couchsurfing.com without raising red flags & recieveing negative responses. I would like to see more people open their homes for transitional type housing with the idea that it was temporary in nature to assist someone avoid or recover from homelessness or to foster budget relocation to a new place. The CS model could be the vehicle to achieve that type of dynamic but I would guess that it would have to be done in a transparent & honest way.
It is rarely any different than flying a sign/spanging, hitchhiking or using rideshares; if we all act like dicks then collectively those who are inclined to help us as individuals will collectively stop helping us all as a group..