I'm not sure where you got the 1-2 years. This kind of thing happens quickly. If dumb money thinks the floor is collapsing, the sell off will be sharp. It would be another SR event, followed immediately by the next bubble.
Right now the "dump money" people think they are smart enough not to sell into another "SR event". So I expect a slow painful downtrend aimed maybe even to single digits.
Nope. The market definitely doesn't work that way. Everyone tries to front-run everyone else. Such a collapse would not be a straight line. It would be a steep curve down. Dumb money would sell coins cheap to the waiting smart money, then buy the coins back later once the price has been shooting up for a while.