god bless you!!!!!While darkness is not a requirement, establishing a normal day/night cycle from the start can be very beneficial and result in happier/more balanced chicks and adults down the road. To heat without having to use light you can use a Mama Heat Pad (there is an excellent thread here on BYC) or a brooder plate as the heat source. I would not use any flammable materiel (ie the tea towel) anywhere near the heat lamp, even with what might seem infallible precautions the two can end up in contact with each other and the results are never good.
As to the temperature, while 90-95 is a commonly recommended range for the first week (lowering by 5 degrees each week thereafter) this is actually erring very much on the side of caution -- rather than relying on the thermometer it is better to use your chicks' behavior to guide your heating. Provide a warm spot in one area of the brooder (if using a light this is directly under the light) but provide ample "cool" space outside of that area (many thing you must heat the whole brooder). This approach allows the chicks to better regulate their temperature themselves. If the chicks are all huddled right under the heat they are showing they are too cool, if they are all huddled as far away as they can from the heat they are too hot.....you are looking for happy chicks scattered about the brooder. It is very easy to overheat chicks and in many ways more dangerous to have them be overheated than to have them be a little cool.