These quotes do not put Lenin in a very good light. The description of what the proletariat 'does' is an obvious figment of his imagination -- what he wished it did, not what it actually does.
In actuality the working class sees nationhood in much the same way as the bougeoisie, as a question of freedom from the domination of some foreign power. Foreign power manifests itself in the form of overt military and police presence; usurpation of self-government; pre-emption of local economic development (in either socialist or capitalist form).
Lenin says the proletariat supports nationalism in order
'to secure national peace (which the bourgeoisie cannot bring about completely and which can be achieved only with complete democracy), in order to secure equal rights and to create the best conditions for the class struggle.'
This sounds pretty vacuous to me. It's not clear what 'national peace' even means. 'Equal rights' is not much better -- equal to what, what rights, for whom? And the last one is circular logic.
The vagueness of it all underlines the potential for opportunism in Leninist doctrine re: nationalism.
mbs
It is not true, however, that the recognition of the right to self-determination equals an unconditional support for all nationalisms, and Lenin made the distinction clear: . . .