Two Year Old Cedar Deck Sealer (DONT USE SHERWIN WILLIAMS PRODUCTS)

I have read numerous posts and I think I have good direction to fix the mess created by utilizing Sherwin Williams Deckscape product to seal/stain our new deck. The new deck was installed Oct of 2013. Given the month, we decided to wait until the summer of 2014 to seal the deck. Since Sherwin WIlliams was (no longer is) a trusted source of paints, I decided to give their sealer a try. The contractor who built the deck power washed the deck, waited 3 days and applied Sherwin William sealer with tint since it provides UV protection.

During Chicago's winter last year (first winter following the application of the stain/sealer) the sealer/stain was coming off in strips. Once the snow melted, it was a mess. We had Sherwin Williams come out and of course, they claim it is due to the improper application, not their product. I checked youtube.com and I saw several videos of decks which looked just as bad as ours. So, if anyone out there is thinking of SW Deckscape, don't waste your time and money.

I just had the contractor spend 3 days power washing the entire deck (about 1,500 sq ft).

So, my questions are:

1. Should I sand the horizontal deck surface before applying a sealer?
2. How long should I wait to apply the sealer?
3. I see that TWP is the best recommended product for sealing/staining- is that what is recommended for cedar decks as described above?
4. Should I use a restore product like Restore a deck?
5. If I use TWP oil base based product, what is the recommended timeframe to reapply (1 yr, 2yrs, 3yrs?) given I live in Northern Ilinois (Chicago area).

I appreciate any and all input.