You had great sucess the first time. I would do the same exact thing that you had great success with the first time 3 to 6 more times. Each year you will have 2 MORE inches deep, rich soil in your great "location, location, location," for some lucky plants. Your garden is two inches closer to heaven than everybody else. Two inches of great soil right where you want it is two inches more then others who did not bother last year to follow your method have to start their garden in this year. Eventually, even if you stop gardening for 10 years, this part of the garden will always be a bit higher and a bit greener than all the rest. Sort of in memory of all your hard work on it's behalf.

A few of them are going to escape and die. When you are really new to this you may agonise over every worm ( I hope you aren't giving them names : -) I'm not sure why they do some suicidal things but they do. All you can hope is that they are breeding faster than they are commiting suicide. I find crispy worms that escaped all the time. As long as you are finding lots of tiny baby worms I wouldn't worry about a couple that got away.

With regard to the heat, yes it will be a big problem. I deal with it here in Florida by partially filling plastic soft drink or water bottles with water and freezing them. I then place the bottles, wrapped in newspaper, in the worm bins. From the way they migrate close to the bottle, they appear to love it.

keep the bin indoors? i live in Hawaii on a daily basis it gets high 80's even 90's at times my worms for the past 2 weeks have been doing great had problems just like you but fixed them. i still am not getting cocoons i think my worms are still too young for that even though they have clitellums already i know they are not fully grown. i keep my bin indoors i got idk maybe 50-100 worms they seem to be doing great. indoors no problems the only problem is space. cannot really keep them outdoors either we have little to no shade at my house. i am using a cooler for my bin the biggest problem i had was air flow. their was the styrafoam padding for insulation at the top and a piece of metal i had to remove both of these and once done my worms got more air and were doing better then ever. next i plan on using a 55gallon drum and cutting it in half since it has no lid on one end then forming together and gluing together into 1 long bing that shallow yet a lot of surface area and raise worms in their