Neutral Wires in series ok?

I'm building my version (ok, exact clone really) of Kal's electril brewery and noticed that his Neutral bus is only half full. Are the neural wires able to be wired in series then? Difficult to trace the wires using the pics

Yes it is perfectly fine. While Kal's individual diagrams show a hot line and neutral line going back to their respective buses each time you don't necessarily need to run one all the way back for each circuit. For most of my circuits on the door side of the panel I ended up combining multiple hot and neutral runs so I could use less wire and not have to worry about running a wire all the way back to the back panel of the box each and every time.

Happy building!

I would increase the wire size, or at least make sure the duty cycle of that conductor is running a lower total current than it is rated for.

When you daisy chain components the current through that conductor is additive!

Dunerunner is correct. You should not do the same thing with ground. All ground connections should terminate at one point. The consequence of having grounds not terminate at the same point is noise. The noise is created by gound currents which are created when there are multiple paths to ground with different impedances. Any current flowing though these different impedances can generate a voltage (noise) and cause problems for the instruments in your control panel.

Even with small current loads, wiring hots, neutrals, or grounds in series isn't a good habit to get into. dunerunner is correct. Wiring loads in series increases the overall current (provided the currents are coming from the same "leg" in the panel) every time you add another. If you have 5 amps on a 14 AWG wire, you're okay. If you've added five 5 amp loads on that same size wire, you now have 25 amps on a wire size rated for 15 amps by the time it gets back to the panel. Sawdustguy is also correct and to add to that, having things grounded at different points (one part grounded to the panel and another grounded to a ground rod in the garage) can also create a differences in potential, resulting in "objectionable currents".
How much extra wiring would you need to run each circuit to the bus inside a panel? $5.00 worth? A 250' roll of 14/2 romex/NMB is about $60.00. That means a little under 21' for $5.00. It's always better to be safe than sorry. Pete