Output optimal trill fingerings
Pyth, 36 * .95 * .90 = 30.78

jd+JrFAQ&lt;*vz,H.xeJhH?&amp;%K-vzlJ2&gt;K0K.q


Test suite

Outputs space separated integers and can handle arbitrary integer inputs, so it qualifies for both bonuses.

Input format:

length
starting finger, ending finger


The output is constructed by starting with a range from the starting finger to the ending finger, then repeating the end of that range and the ending finger the necessary number of times. Exiting is done via explicit checks for the length of the second step being odd and positive, or else .q, Pyth's exit function is called.