For this topic it might be easier to know it is a matter of a simple foul versus a personal foul. Roughing is a personal foul. Running into the kicker is not a personal foul.
So if team B holds or is offsides on a succesful kick. A normally elects to take the points and penlaties are declined.
Roughing the kicker, facemask, etc then A can keep points and enforce on kickoff since they are personal fouls.
Fouls During a Try Before a Change of Team Possession
ARTICLE 3. a. Offsetting fouls: If both teams foul during the down and Team B
fouls before the change of possession, the fouls offset and the down is repeated,
even if additional fouls occur after the change of possession. Any repeat of the
down after offsetting fouls must be from the previous spot (A.R. 8-3-3-II).
b. Fouls by Team B on a try:
1. When the try is successful Team A shall have the option of declining
the score and repeating the try after enforcement, or declining the
penalty(ies) and accepting the score. Team A may accept the score with
penalties for personal fouls and unsportsmanlike conduct fouls enforced
on the succeeding kickoff or from the succeeding spot in extra periods
(A.R. 3-2-3-VI; A.R. 8-3-2-II; A.R. 8-3-3-I; and A.R. 10-2-5-IX-XI).