1) I don't think see any way this can be avoided. The top Bitcoin developers will always be in demand by the top Bitcoin-related companies, and developers are free to work for anyone they want. I don't think it's really a problem in the long run. If people really believe that the Bitcoin Core project is compromised by developer self-interest, someone will start a BitcoinXT-like project, and Core will no longer define what IS Bitcoin.
I would caution that you shouldn't assume out-of-hand that developers are acting purely in their own interest, like Dr. Stolfi does. Isn't it possible that the Core devs who are also Bitstream devs have thought a lot longer and harder about this problem than most of us, and realized (like I said earlier) that there really IS no way (as of now) to have Bitcoin be both scalable AND decentralized, and set about building a project that might insure that Bitcoin will still be usable anyway? Sure they MIGHT be acting solely (or even partly) in their own interest. But making money out of having the foresight to anticipate this problem does not, a priori, mean that their solution is not the RIGHT solution.
They don't have to be evil people to be biased in their judgement.
2) I can't parse this. If you think a protocol must have multiple, conflicting versions of itself, you may not understand what the word 'protocol' means. If you mean something related to alt coins, I would point out that there are plenty of those already.
To compare: we have firefox, chrome and IE browsers on the HTTP. We have~15% of nodes running XT, a few running old obsolete versions of core and everyone else running core. That's a monopoly when a supermajority (or even a super-duper majority "consensus" need to implement a change. The biased core devs and greedy miners have veto power.
Scaling is a trade-off but a necessary one because we are reaching capacity. Let's use a gold mining analogy: In the free market, there would be no way a placer miner (guy with a shovel and a pan) could consistently compete against a large mining corporation. If you change the mining rules to make him more competitive, you have left the free market.If you change the rules to make him LESS competitive, you have also left the free market, but that is not what's at issue today. It's called "capitalism" because you need capital in order to increase your productivity.
Code development is not constrained by capital (very much) because the limiting component is creativity. There is nothing magical about being a core dev. It does not automatically make you wise and just.
The market will ultimately decide and if bitcoin doesn't scale, it may well decide on an altcoin.