
My guess is: Conduct all fouls in the order of occurence:
(1) Dead Ball Offside(5 yards) ~ Defense / 1st and 10 @ the B-45 yard line.
(2) Dead Ball Delay of Game(5 yards) ~ Offense / 1st and 10 @ the 50 yard line.
(3) Dead Ball Personal Foul(15 yards) ~ Defense / 1st and 10 @ the B-35 yard line.
(4) Dead Ball Unsportsmanlike Conduct(15 yards) ~ Offense / 1st and 10 @ the 50 yard line.(Ultimate spot following all penalty activity.) 
If these are the four fouls you've got, then this is the correct spot. But note that penalties 3 and 4 should not be separately enforced; rather, they should offset. (It doesn't make a difference in this situation, but if half-the-distance considerations came into play, then offsetting would be different from enforcing both in succession.)
A collection of DB PFs and USCs, that includes at
last least one by each team, gets offset with no yardage assessed. Those other two fouls, not being PFs or USCs, do get administered in chronological order.