What comes next in each of these sequences?
$$\begin{array}{align*}\textbf{ 1 }&\text{J, KK, LLL, MZ, A, BO, ?}\\\textbf{ B }&\text{HNAKXR, EERREA, LOGYND, INOPOO, ?}\\\textbf{ C }&\text{NMLLARY, JBZALOY, KMMRA, DBJTML, ORMSLBL, ?}\\\textbf{ 4 }&\text{C-N, E-N, NW-S-NE-C, S-SW-W, WSW-SE-NNW, ?}\\\textbf{ E }&\text{FIRST, WELL DONE, PARKER, RIVER MOUTH, RIVER MOUTH,}\\\textbf{ }&\text{DANCE, ?}\\\textbf{ F }&\text{FILLY, DOE, FEMALE, HEN, BITCH, ?}\\\textbf{ G }&\text{FREDDIE, WILLIAMS, DOWN TO, LIFE ON, DROPS OF, ? OF}\\\textbf{ H }&\text{VIENNA, BRUSSELS, HAVANA, BERLIN, MADRID, ?}\\\textbf{ I/9 }&\text{ZXV, PRMT, JFVVM, QZXP, GVM, MRMV, VRTSG, HVEVM, HRC,}\\\textbf{ }&\text{UREV, ?}\end{array}$$
Fill out your answers in the grid below and observe the final sequence in the highlighted cells. Find the missing letter, but make sure you take it one step at a time.