So here are some points I disagree with you. 
1) Extraction of surplus value. This is predicated on the assumption that bosses do not do any "job", that is, do not add to the surplus value, which in a lot of cases is simply not true .
Especially if we are talking about a small scale business, which constitute about half of US economy, bosses quite often contribute to the added value and bear associated costs, eg. distress (Cocker et al., 2013). 
2) Democratic control over the working conditions. Although there are some firms (Mondragon in Spain, for example) that use the model of elected managers, I highly doubt that this is viable in a long term.
The reason is that in political democracy you don't have a motive of competition, a major driver of innovation and quality (Gilbert, 2006). 
2b) As Kremer (1997) argues, cooperatives are not efficient at allocation of benefits to the different employees, thereby reducing desire to participate and lowering efficiency.
3) If you mean worker-ownded companies that's a different ballgame and already exists in form of Ford for example.
4) Removing the competition requires planning; planning requires central authority, which tends to become undemocratic. Evidence of that we can find anywhere from America (Cuba for example) to Africa (xx) to Europe (East Germany, Poland and Hungary).
Given that countries that diverse in their culture and economic development invariably devolve into authoritarianism (at best) compels me to think that tyranny is not a bug, but a feature of socialism :)

Gilbert, R. J. (2006). Competition and innovation. Journal of Industrial Organization Education, 1(1), 1-23.
Cocker, F., Martin, A., Scott, J., Venn, A., & Sanderson, K. (2013). Psychological distress, related work attendance, and productivity loss in small-to-medium enterprise owner/managers. International Journal of Environmental Research and Public Health, 10(10), 5062-5082
Kremer, M. (1997). Why are worker cooperatives so rare? (No. w6118). National Bureau of Economic Research.