Do people have planets on cusps the same way people seem to have the sun on a cusp? And how would that work?

Not on house cusps, but on the cusps of signs, like if your sun is on the Cancer-Leo cusp. Could someone's Venus be on a Cancer-Leo cusp too, or is it strictly Cancer or strictly Leo?

No such things as cusps in real astrology. 29 and 0 degree planets of a sign are critical degrees.

Many astrologers consider 0 and 29 degrees of any sign critical degrees as well. The 0 and 29 degrees are more crisis-oriented points, especially in predictive work.

If a natal planet is found at 29 degrees of any sign, also known as the Anaretic degree, there can be some real issues with decision-making in that part of the personality represented by the energies of the planet. The native may evaluate and re-evaluate situations before making a move one day, and the next day, jump into the action without listening to himself or herself! For example, if Mars is at 29 degrees, the native may devise many plans of actions, worry excessively about the possible actions and different routes to take, and then execute a spontaneous action that is contrary to the decision!

I know of a woman whose Juno is at 29 degrees, and despite the fact that she has many theories about taking relationships seriously, jumps into them quickly. A man with 29 degrees of Mercury agonizes over decisions in his life, and vacillates between talking too much and too little.

Besides decision-making problems, vacillation, and jumping into situations blindly, the 29th degree is also associated with a sense of urgency. It's the last degree of the zodiac sign, and there can be a real sense of urgency surrounding the characteristics and associations of the particular sign.

Yeah, I think they do...it must be like the Sun case.

no

it defeats the order and beauty in astrology, those are the jobs of planets aspecting each other, not struggling between one placement, imagine how someone would feel if he had a bunch of his planets on cusps, and how it aspected other planets, that would be turmoil.

i dont know who even thought of the idea but it doesnt make sense one bit.

you are what you are i say.

no. Your Sun and Moon signs are affected by when you were born.

Your house signs, which is actually what you are talking about here, are not based upon your birthdate but upon your dominate Sun sign.

I know this answer is probably as clear as mud for you, sorry! This is the way of horoscopes.