As working in archviz.. well sometimes, the most difficult part for me is having a discution with an architect.. Reading plans is kinda easy, but when you don't understand something, you've got to use the good words when talking with the client. Luckily I'm not alone and every day I learn stuff. I got a lot of luck finding a job, mainly because my renderings impressed my employer. I'd like to fully work on archviz, learn more and more, but I don't think I would be able to find another job in archviz if I had to lose my current job, mainly cause I simply don't have any architectural qualification, so I guess it's something you MUST have. At least for the understanding of technial stuff.