my best of 42.5 must be pretty accurate after all then, because I think that is what I had for 53.32
for mission 2 and 35.00, what I do is lightdash the first set of rings after you land, then do a spindash jump while collecting the next set of rings and aim my jump to the left and lightdash that huge chain of rings, then spindash into the loop(you must hit atleast 2 boost pads or you will go slower than normal) I jump before hitting the ramp at the end of the loop and aim that jump at the next ramp, hitting the check at 15 I believe I lightdash the set of rings by this check and then spindash to the spring. from here just spindash twice as you do in any other mission, hitting the spring. Spindash down the slope getting most of the rings (I believe you need atlwast 65, maybe 67) then jump out of the loop as you do in M1 to skip the rest of the loop and the ramp.
From here I found a new strategy which got me such a great time(The second-best time was 37.2 when I got 35.00) once you land in the robot area, lightdash the rings and you will kind of zig-zagas you lightdash, and if all goes well you will automatically hit the boost pad, and from there if you time it just right you can instantly jump+homing attack from the boost pads which will let you hit the 2 ring boxes without wasting ANY time, and should easily get you a 35, and maybe a great new record of 34 if you make a nice flawless execution. I got tired of playing and just settled with 35 flat, which is still a great record by my standards.. but it can be beaten!
This does not work every time, but I had fairly good consistency when I did it, maybe 50%.
I DID tape 35.00, but I searched my tapes and could not find it, but this "guide" I just made should be good enough.. if you don not understand it exactly I can always make a slow run showing just the strategies I am talking about.