Lemon Blue crossed to Brown Red will make equal numbers of both colors. Following the explanation I posted above, the Brown Red parent is bl+/bl+ and so only has bl+ genes to pass on, while the Lemon Blue is Bl/bl+ so has both Bl and bl+ it can pass on. Since there's an equal chance of Bl or bl+...
Yes, Blue x Lemon Blue should give you the same ratio of BBS offspring as just Blue x Blue, but in this case likely showing some color leakage that resembles the pattern of coloring on the Lemon Blues.
Brown Red crossed to Brown Red will only get you Brown Red, yes. Even if their parents were Lemon Blue.
If it helps, I'll explain a bit more about the inheritance. The reason why Lemon Blue does not breed true is because the blue gene is partially dominant. What that means is that the...
Lemon Blues breed like plain Blues do, producing blue, black, and splash versions of the variety when bred together.
Lemon Blue x Lemon Blue = 25% Brown Red, 50% Lemon Blue, and 25% Lemon Splash offspring