I'm just going to address your specific example, since your other questions about SNLT can be answered indirectly through my response to the example you presented.

In your example, SNLT to produce 1 loaf of bread=1/3hour. And the price that corresponds with that SNLT (the average weighted price of a loaf of bread on the market)=$5.33 In the case of the worker who produces 100 loaves of bread, the value of what he is producing in one hour of production=33.33 hours. If we want to convert this to dollars to see how much his 1 hour of labor is worth in money, this would come out to 33.33x5.33=$178. His wage is $25 for that 1 hour of labor. 178-25=$153 which is the amount exploited. Obviously since you set costs to $2 per loaf and sales to $3 per loaf, it's impossible to actually pay him this amount. So this poses problems for your hypothetical example, but you did entirely make up these numbers so it's understandable. If you said cost per loaf was $1, then your scenario would hold together.