Kaya

Can no problem. At my childcare they serve kaya bread for 18 months old youger Toddlers.

The sugar content in Kaya could be too sweet. It may spoil the child taste bud imho

Depends on your threshold for sugar... haha. Alternatives are sugar free jams.

18 month should be fine. If he/she not allergy to egg. Kaya contains egg

If child is not allergic to eggs, yes can give in small amounts.

should be fine. But better buy a new one to avoid any problem

Not too much though, just spread very thinly on bread etc

Yes can just limit the amount due to sugar content.

It’s ok with moderation because kaya is sweet..

Not too much, spread thinly in bread etc