Hey mate,
1) If you want to make your concentrates edible safe, I would personally avoid using solvents to extract the thc. There is a lot of debate about this subject. From my experience, using solvents to make extracts for edibles is not only a complete waste of time and product but you also lose a lot of the medicinal properties in the extraction process.
You can make edibles from the kief. It's not beneficial refining the kief into a concentrate and then refining the concentrate again to make butter to make edibles. You will get the same results using the kief product for your edibles instead of using the refined concentrate.
If you are really stubborn like me and you want to have a very strong concentrate to use for your edibles your best option is to make full melt bubble hash. This will give you the strongest possible concentrate without damaging any of the medicinal properties. You will be able to vape the hash or use in edibles. Win Win.
Now onto answering your questions.
You most certainly do need to freeze the product. You will need to freeze the product several times at several different stages during the process of extraction. If you want a safe, potent product. You need to follow the correct instructions. Failing to correctly purge the concentrate can get nasty. A lot of people cut corners and try and speed things up. DO NOT be one of those people. Do it right the first time and you will be rewarded with some very nice end product. This is a slow process and if you want the best results possible for the product you are using, you will need to exercise your patience.
1. Freeze Your Solvent and your Material. The longer the better.
2. Drown your material in solvent of choice.
3. Strain immediately.
4. Place strained solvent back into freezer. The longer the better.
5. Steps 1 and 3 can be repeated several times for a more pure concentrate.
6. Steps 2 and 3 can be repeated several times for more yield. Quality will decline.
7. Remove solvent from freezer. Strain immediately.
8. SLOWLY evaporate solvent. The longer the better.
9. Steps 1-8 can be repeated several times.
The texture of the concentrate will vary depending on the temp at which the solvent evaporates. If the solvent evaporates at a consistent LOW HEAT, you will get shatter. If it evaporates any other way the texture will vary. Keep in mind. A less pure product will have a more sticky, goo like texture regardless of how you purge. It will most likely be darker and not taste as smooth. The higher quality end product will have a higher chance of being glass like. It should be transparent and snap very easily. It will be easier to handle and a lot less messy.
2.
The kief crumbling and not being malleable is caused from two things, or a combination of both.
a) Kief contains plant material.
b) You are not applying enough heat while you are pressing your kief.
If you want your kief to stick together like hash you will need to apply pressure and heat. I use a wooden chopping block and the wife's clothes iron to achieve this. Turn on the iron let it heat up then turn it off. When you can place your finger on the iron element for 5 seconds before it starts to burn your finger, you are safe to press your kief into hash without damaging the product. If the iron is hurting your finger it's going to hurt your kief, so be cautious with the heat setting.
I use non stick oven safe baking paper. Spread out your kief, fold over the paper and ask your wife for advice on how to iron clothes. Follow her instructions, right after the lecture about using the iron on a chopping block. You will need to fold the baking paper several times in this process until the kief becomes a solid mass of hash.