Hello and welcome.
I searched separately for the bike you linked to (no offence, but links in first posts can sometimes be dodgy). I have a trailer for my 4 year old. Personally I would sooner have her behind me than in front. Trust me, they always let you know if they're not happy. You can get also front mounted seats like the Bobike or Wee-Ride, I know that there are plenty of pros and cons for these but they would give you your little one close to you without needing quite so much infrastructure ahead of the front wheel.
I think the great thing about trailers is that in the worst case, if you go over, the trailer stays upright or only tips onto one side. They are low so it's not far to fall. They also have a decent roll cage for the child's protection, and are easily detached if you need to leave the trailer at nursery or wherever and ride on elsewhere yourself. The bike mounted seats are the best for versatility though, as you don't have to worry about fitting through narrow gaps or where to park.
Good luck with your choice, riding with a child is great.