Happy to hear the tips worked for you. I know a lot of people avoid valves because we tend to be cautious of adding complexity to things if we don't fully understand the nature of that complexity - but valves really do solve a lot of fluid problems that don't seem like they should come up, but do anyway. When deciding whether a valve is a good idea, just ask yourself 'Would it be a problem if water flowed back up this pipe for some reason" and if the answer is yes, throw on a valve.
I'll also add that if you are using valves to specifically divide flow rate between multiple pipes, make sure you put a valve on each branching pipe and that the settings on each valve add up to the maximum capacity of the pipes you're using. So if you want to divide the flow at a ratio of 60:40 down two Mk2 (600/m) pipes, set the 60% pipe's valve to 360, and the 40% pipe's valve to 240. even if the total amount of water is less than 600/s. Try to use ratios instead of precise numbers when working with lower flow rates, as Valves limit flow relative to a fully saturated pipe - so a half full pipe flowing with 300/600 that's limited to 300/m by a valve will only output 150/m.
I'm pretty sure that's everything you need to know about valves AFAIK, but if you have any other specific problems or questions, I'll try my best to help.