Hi Jerome and welcome to cr0

A bit of a mixed bag of questions Jerome

1) In my opinion, if you wish to avoid burning the spices, simply mix the powdered spices in water to make a runny paste of the spices. This way, they will not get above 100C until the water has evaporated. You can also mix them with oil, if you prefer, but I personally can't determine much difference between the two.
You can do this with any of the recipes on this site (bases or otherwise) that call for frying spices (to avoid burning them)
2) The easiest base is probably the one that looks easiest to you! I expect it would be the one most clearly written and with the smallest number of simple ingredients and steps. Look at this thread which might be of help:
https://curry-recipes.co.uk/curry/index.php/topic,2203.0.html3) You should only get a "rough, sawdust flavour" if you add stale spices (use fresh) too much powdered spice (don't use too much) or under or over cook them (don't do either or they will be bitter)
Hope this helps? Please let us know how you get on and please post your recipes and results (plus photos)
