Networking Best Practices Question

Hello, I'm a sysadmin with minimal networking knowledge. Our network engineer quit and I've been tasked to clean up his mess. He was very knowledgeable but tended to do things quickly rather than correctly and once it works, stop and move on to another project without cleaning anything up. For instance this is one of our IDFs and sadly that isn't the worst one we have, just the only one I have a picture of.

Questions I have since I'll basically be replacing all networking switches is:

1. What is the proper method/ best practice for setting up trunks between all the switches? For instance can I have 4 switches all on Trk1 or do I need to have unique trunks for each switch? (all switches will have all VLANs trunked to them)

2. I've heard that for short runs (~1-2m) copper is technically faster for trunking than fiber (edge switches have only SFP so only 1gig either way), is that true?

Thanks for your help.