i dont believe in crying it out(however if someone insists on doing it, i agree with the woman saying to read the book, as many people think "ferberizing" is just letting the baby cry until he passes out, which is completely wrong). to have a routine every night for over a year, and now change it by not comforting when he is going to sleep seems like it would be very upsetting to a baby who doesnt understand.
for your concerns, i would think it may just be a phase at this point. he may be just overwhelmed at all the new tasks he is accomplishing. his mind may not be able to settle as easy. he may also be trying to transition to one nap and just not be able to get in a rythym. he knows he isnt tired in the morning like he used to, but cant figure out when to get to sleep. keep experimenting with time changed BUT make sure you try each time a few days in a row. you dont want to do 10am monday, then 11am on tuesday, as it will confuse him more. pick the time where you see him looking tired, and go from there.
i also have no problem with letting him find a new place to sleep. see if you can get him to lay on the couch when you think he is tired.
is he happy without the nap? if he is happy, there is no reason to worry. my daughter had LESS than 12 hours sleep total at 1 year counting naps and nightime. and remember, for his age the average is 14 hours. if he is at 12.5, he is only 1.5 hours less. and average means some are more and some are less, and thats completely normal.
doctors go to medical school. they learn about health and illnesses, how to treat thing, ect. now when you are talking about a subject such as sleeping, that is not a medical issue in the context of asking how to get a child to sleep. there are so many books about the "right" thing to do, some by doctors and some not. but the bottom line is, they are only that persons opinion. if there was truly a medically proven sleep solution, all doctors would be agreeing on it, but they dont agree because its only their opinion. medical advice is how many hours is the average a 13 month old sleeps, not how should i get my child to sleep. besides, sounds like he is the best night sleeper you could ask for. so what if you may have to work a little harder in the day, at least you sleep:) good luck, hopefully he will be on track in a few weeks, thats how long my daughter took for sleep changes!