Just thinking out loud here. We have not only LE working on this case, but several other agencies assisting. They've used drones, divers, search dogs.
Now, this kidnapping scenario doesn't fit for me because I truly believe that if this was the case, they would have more information available to the public about her bike, her helmet, any clothing she was thought to have on that day, etc. You can't tell me that the sheriff is alone in his thinking that something violent occurred with Suzanne. I highly doubt that the FBI would be wasting their time digging through cement and dirt because he was wrong in his assessment of this case. No, I think they are in agreement with him that something sinister happened to Suzanne, not far from home.
We've never heard of whether or not she had those sneakers for bike riding that many bike riders have.
As far as her cell phone- did we ever hear confirmation that her cell phone was at home, or was that a rumor?
I am also certain they have checked alibis and know where every person close to Suzanne was during the time period that the sheriff asked people to hold on to their videos from their cameras during those dates. So they know who was in the area during that time period and who wasn't.
We also don't know when she was last physically seen alive, or when someone heard her voice on the phone. Texting won't matter at that point, as anyone could send texts from Suzanne. However, maybe when she was still alive, there might be some texts they've gone through to see if she was communicating to anyone about anything going on during that time that may have been stressing her out.
Other things I have thought about- I am sure LE checked things say, in her kitchen to see when she may have last eaten- were there dishes in the sink, and if so, how long were they in there? Any mold growing on them, any odor from spoiled food or trash not being taken out? Was there any baked goods or bread on the counter getting moldy? Did she have something taken out for dinner that sat on the counter? Fruit spoiled? Any insects around food on the counter?
Any laundry left in the washer machine that may have that distinct smell of not being taken out to dry?
Footprints in the house- muddy or bloody? Any articles of clothing torn or with body fluids on them? Was the house spotless and floors bleached clean?
We don't know much of her usual habits- if she had a daily routine. What time did she normally get up? Did she eat breakfast first thing, or pray first thing in the morning? Or go out for a bike ride or even a walk? What time was her usual bed time?
Just things I am pondering while trying to sort something else out.