It's possible.
Yes, this is possible.
Sugary treats do not usually cause cavities in horses . Horses' teeth continue to grow all their life and need to be looked at once a year. Food trapped between the horse's teeth or growth at odd angles are more likely to cause decay. If you are worried about the amount of sweet treats you give, try some treats designed just for horses. A friend of mine has a pony that is not allowed sugary treats as he is prone to Laminitus so she buys sugar free sweets.
yes
yes
Yes.
yes
Yes, too many sugary treats can and will give your horse cavities.
yes
True
Horses are not plagued by dental cavities, so not sugary treast wikk not cause cavities. Limiting the amout of these treats is cautioned though because the horse may come to expect the treats and become 'spoiled', with an increased tendency to bite when a treat isn't given.
True
it can yes, but it is just like our teeth, if they have too much it will, but its OK to have sugary treats occasionally.