• Ability to combine adjacent manoeuvres: Often, I want to make multiple changes to my orbit at the same time, e.g. changing inclination and also adjusting periapsis, and it is more efficient to do so as a single burn. Currently, to do so, I have to use the manoeuvre planner to set up a node that does one of the things I want, then try to manually adjust it to do the other as well. I therefore propose adding a button which would merge two adjacent manoeuvre nodes into one node with a burn value equal to the vector sum of the two nodes.
• Currently, the Adjust Inclination function only offers three timing options: equatorial ascending node, equatorial descending node, and fixed time. However, for elliptical orbits where the equatorial nodes are not near the apoapsis, it is often more efficient to do an inclination change at apoapsis rather than either node. I therefore propose that two new timing options be added: apoapsis, and 'to minimize delta-v'; the second one would do a simple guess-and-check search to find the point in the next orbit where the requested burn has the smallest delta-v cost (which isn't too hard; it has to be somewhere between the apoapsis and the higher equatorial node).
• Somewhere on the Manoeuvre Node Editor panel, display the total delta-v cost for the node. Currently, for any node but the first, the only way I can see the total (rather than 3-component) delta-v is by mousing over it in the map
• Make the delta-v component displays left-justified; the Manoeuvre Planner generates nodes with umpteen digits, and with only the rightmost 6 or so digits visible, there's no easy way to tell whether a component is 112.6877394 or 0.0007394.
• Manage manoeuvre sequences: When performing a complex orbital change, there are often many different ways to go about it, and I want to find the best one. (My periapsis is too high, my apoapsis too low, and I need to correct my plane. Is it more efficient to lower my periapsis then raise my apoapsis, or the opposite? Or should I raise my apoapsis way up, do the plan change, then match hights? And if so, is it worth it to drop my periapsis before raising my apoapsis?) Currently, what I have to do is create a manoeuvre sequence, write down and add up the manoeuvres, delete them all, repeat for each possible plan, then select the best one and recreate it from scratch. I therefore propose the addition of two functions: a display on the Manoeuvre Node Editor panel giving the total delta-v for all currently planned manoeuvres, and the ability to save and restore all currently planned manoeuvres. (Note: Also have it display the total delta-v cost for the currently saved manoeuvre plan, for quick comparisons.)
• Adjust tangential rendezvous: One situation I frequently find myself in is that I'm trying to rendezvous with a target, and I've got myself into an orbit which is tangential to the target's orbit at some point, so I create a node at the tangent point and then adjust the prograde vector such that we both reach that point at the same time on the next go-around. I'd like a function which does this for me. (Note: such a function must be sure to preferentially find solutions which reduce the velocity matching burn rather than increasing it.)
• Fine-tune closest approach at time ahead: Currently, the 'Fine-tune closest approach' function only offers one timing option: 'to minimize delta-v'. However, past a certain point in the orbit, the point of minimal delta-v is always right now. For large vessels which are slow to turn, it would be better to be able to force the function to calculate a node at least a certain time in the future, in order to give the vessel time to orient before the burn. Also, for larger orbits, I often find that the first fine-tuning burn isn't accurate enough, and that subsequent burns fail because they are too small to be performed accurately, so I have to keep awkwardly time-warping ahead a bit before trying again, looking for the point where the correction is large enough to do accurately but not so large as to waste delta-v; being able to plot burns at various distances ahead would allow me to find optimal correction points and then warp to them.
• Auto-recalc mode: For large orbits, planning a burn far away is tricky, because floating-point errors and such are enough to significantly change the required burn. What I often find myself doing is setting up a burn with the manoeuvre planner to get the approximate time and direction, time-warping to a little ways away from it, then deleting the node and recreating it with the same parameters to get the correct values. What I'd like is an option that does this for me: it remembers not just the node details but what you are trying to do, and every time it drops out of time-warp to correct heading, it also recalculates the node itself.

Pushing fine tunings ahead can be done currently rather simple by just planning a node somewhere and THEN letting MJ calculate the fine tuning.
It will put it behind the previous node and therefore you can force it to do it later where the burn isn't in the <1m/s range anymore.

Ideal would be though if MJ would automatically shift ahead in case of too tiny burns.