Resurfacing a raised deck; want waterproofing (dexerdry); need gutters? Also: comment on plan?

Question

Thanks for reading. I'm starting the planning stage of a raised deck (without space underneath) overhaul/resurfacing. I have one concrete question regarding waterproofing but would also appreciate any critique, suggestion, information regarding cool products, things you would do if it was your deck or any general info about my plan (for those that have time) because you don't know what you don't know right? If someone has been through this before, any info you can provide would be a huge help I'm sure. THANKS!

Question:

• I really would like to have a waterproof solution. I plan on using dexerdry (dexerdry.com; imo better solution than any other underdecking if it works for me). Manufactuer says it's possible that I could put gutters off my deck, but did not say it was required. We get a decent amount of rain here in Maryland which is currently managed by two drains underneath my deck. Should I be planning for gutters for a deck?

Bonus Question for those with the time:

• does the plan below reasonable and is there something else I'm not considering?

PLAN

• Select composite deck brand material, railing style, light styles
• Speak to electrician about installing low voltage transformers off of sconces above and below deck (above - to light deck, deck stairs, and another set of stairs off the deck, below - to light underdeck space
• Purchase lighting to make sure low voltage led solution works well given number of lights and length of run
• Purchase materials (deckboards railing)
• Have electrician install transformer and hookup
• Remove old railing and deckboards
• Inspect and treat old deck frame installation and prepare for new deck
• Install centerboard and gutters in deck center per dexerdry instructions Deck is 30 ft long and will need a centerboard cut from 16ft boards on either side per dexerdry instructions.
• Install necessary lighting cables
• Install deckboards and stairs
• Install railing using existing posts or replace with top mounted railing and connect lighting
• Install facia (and gutters?)
• Replace hardiplank that is coming off

I admit the last steps aren't fully fleshed out yet, so I have more research to do there.

Answer 1

If anyone wants to know what I ended up doing as part of their research:

• I took down the deck to the footings because there was just so much rot and I wanted to replace the 4x4 with 6x6s per code and because of the eventual worsening collar rot
• I went with Trex Rainescape over dexerdry because of the difficulty of install against the wall and because I would have to pitch the deck and I didn't want to do that.
• I didn't replace the footings so the posts are still buried. To protect it from future collar rot I treated with extra wood preservative, a coat of flexiseal and a heat shrink tar-like product called PostSaver.
• Didn't need a electrician just a sconce with an outlet, remove the outlet, put the transformer inside and run the LV wire under the railing