The sizing on this ad is so confusing. i cant tell if these are men or womens sized shoes. i wear a womens size 8. what size should i buy?

One size up than women's size. But of all my three Top & Brazil models I say they are a bit (half or full size) bigger. I wear EUR 43 or US 9 and the 44/10 I owned were a bit too long so i often tripped, 43/9 are difficult to find.

I'm looking for the heavy rubber on the bottom like the ones from mexico called calzaletas. they were bullet proof. do these have that heavy rubber?

They do sell calzaletas brand on amazon. Havaianas sole material is a nice balance between soft and durable, but it’s not very “tough”. If you step on a nail wearing these it will probably go through.

Is there anyone else with an unequal walking pattern who can comment on the comparative durability of these flip flops for your situation?

I have had four (4) pairs, 3 Top & 1 Slim. Once I attempted to go sightseeing with my girlfriend with my Slim model and after 1 block I figured they were not going to be comfortable for heavy walking. I used the Slim to wash the car, the beach or at home. The Top/Brazil model models are MUCH MORE comfortable due to their thicker cushioned sole, these are my favorite but they seem not to be too durable at the toe. I use them at home or at the beach. The heel part of this (Top) model is of much better material and construction than my now defunct Teva Original sandals. I like sandals that look great, are comfortable and have that cushiony feel that make a pleasure to walk on and these fit that description although it is a bit pricey for a blank piece of rubber without the flag or the colored Havaiana tag. However, I wouldn't go sightseeing on them unless a car where the main means of transport.

How do these flip-flops ship? ( In a bag, shoebox, etc).

They come in a bag. Just so you know....these flip flops are women sizes. The description is incorrect. I ordered what I thought was a man's size 8 and got a woman's size 8. Needless to say they were way to small.