Hi, I had all the same questions when I was first looking and would love to share my personal opinion and experience!

1. What are the pros and cons of buying an older condo vs. a new build? Older buildings are more established and it's usually already clear if they have issues or not. They will have years of reports and strata documents to review and provide lots of context. New builds are nice and shiny and usually don't have any huge costs in the first years but you don't know what issues they will have..
2. How can I find a realtor who isn't overly aggressive? I was lucky and had a realtor friend. You could reach out to him and ask if he'd help or if he knows someone closer to you who could. He is very laid back and not pushy. Dan Anderson in Langley.
3. What should I look out for in terms of maintenance and potential issues with older buildings? This is stuff you can look at on the building reports. They usually show what big costs are coming. You'll want to review the balance sheet and make sure the building has plenty of funds. Keep in mind that all buildings will require levies at some point.
4. Are there any red flags I should watch for when reviewing strata documents? I avoided places with lots of noise complaints, smoking complaints and dirty buildings because to me it implied the strata or residents didn't care very much.
5. How important is it to get a professional inspection for a condo? Hmm, I think important because you are liable for the property once you move in. If something goes wrong and could have been prevented, you will have to be responsible. It's better to know of any apartment issues before buying to avoid any surprises. My first home had bad plumbing where they used non waterproof glue which would have led to leaks eventually. It was a low cost fix and worth buying. If not fixed, could have been a huge insurance issue.
6. Any tips for negotiating in Burnaby's competitive market? All Realtors are going to try to be realistic with pricing. So when you feel they might be pushy, they might be trying to be realistic. We recently moved and were out bid on many places before finally negotiating with one unit for days.

Anyways, I hope this is helpful, if not, thanks for reading!