Drum occasionally will not turn unless manually turned a few times before start; can here a thud each time manually turned.

sounds like spark timing is way off, almost to a backfire. you probably need a repair manual to troubleshoot.
try here: http://www.manualslib.com/

Does the gas odor occur all the time, or only when the oven is in use ?

If you can turn the drum and then the dryer starts you have a bad motor. The way the dryer works is when you initially push the start button, electricity is sent to the start winding, or stator, of the motor. This will in turn start the motor turning. From there the stator will drop out of the electrical process and at the same time the run winding, or rotor, will take over and the motor will continie to run. Your stator is damaged, has a burn spot, etc so by you turning the drum, the belt around the drum is moved which is attached to the motor pulley. You basically take the place of the stator. Long story short, you have a bad motor.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/jason_4570d45317834dd3

sounds like you've either got a stiff motor or gunk in the drum making it difficult for the motor to turn. When the fuse blows the drum won't turn at all but as yours is trying to turn then throwing the fault up it sounds like something is causing too much resistance

there is a sensor located beneath the lint filter, more the likely the dryer sheet residue is on it, gently brush it off, it has two screws. As far as the loud thud noise is/may be a problem with the drum/rollers/glides/belt/idler arm/motor Here is a website that will assist you, once the filter light goes off and the drum will not turn.Good Luck Tim

http://www.partselect.com/dryer+dryer-wont-tumble+repair.htm

http://www.partselect.com/dryer+dryer-wont-tumble+repair.htm

Is the "thud" sound after start then put in gear or a "thud" just after starting. If "thud" after in gear, could be a CV joint wearing out

Hi,
Most model dryers are supported at thge rear of the drum with a bearing configuration, but usually the front of the drum is supported by some lining pads or guides. These help hold the rotation of the drum concentric. It sounds like your drum is not spinning concentric. My guess would be that some new guides might need to be installed.
Hope this helps...

This sounds like the motor that drive the drum has packed it in could be the capacitor or the centrifugal switch cant say with the amount of info given. I am quite sure it is with the motor as manually turning it is assisting with the start up of the motor

Sounds like the belt is slipping

I used to have a whirlpool fridge, they are the ones who make kenmore too. It used to make a loud thud noise. It was the compressor turning off. sometimes it was loud enough to wake me up at night. It did this for years and I never had any problems with it. when I purchased a larger fridge I sold it to a friend and its still working today. If you can tolerate the noise I wouldn't worry about it unless it starts giving you trouble.