Don't you think it is odd if she spoke to all those people that she never gave a complete name and a motive? From there it would not take much to get to the truth, imo. Things fall into place quickly when you are going down the right path to the truth.
I couldn't agree with your last sentence there more! But with your first - I'm not as sold.
To your last point, and to the contrary: it requires more leaps of faith in my thinking to believe this was a self-inflicted or suicidal action. There are a few ways of looking at this to suggest that's the case, but here are a bunch off the top of my head:
1) # of people who die against their will (murder or accident) via fire vs. # of people who choose to die (suicide, protest) via fire - how does this compare?
2) Friends and family testimony - was Jessica making plans for her future and/or looking forward to upcoming plans? Is there anything to suggest she may have been very depressed or contemplating suicide or has she attempted any sort of self-harm in the past? This isn't necessarily an either/or, just two lists to consider.
3) Source of the accelerant, typified only as "a flammable liquid" by reports (credible sources) - What was it and what was the source? Was there a container? If so, were there remnants of a container (melted plastic, metal, etc.) in or around the vehicle? If not, what might the original source have been + from where? Let's stop and brainstorm *how* an accelerant could have come to be in Jessica's car and on her person.
4) Credible reports that say investigators believe there is a "strong possibility" someone else was also in the vehicle that evening. Worth considering.
5) Jessica's phone records, computer, personal letters, journal, etc. - These will have been searched and may point one way or the other as to suicide or lack thereof.
6) Witness testimony of the fire chief + first responders, some of which has been kept confidential from the public. If what Jessica was able to communicate was anything suggestive of self-inflicted harm, why is there a search for a killer? If she was suggesting someone else had hurt her, why is there a question of suicide?
7) If she was indeed found *outside* of her vehicle, which was in flames, that suggests she was trying to get out or away from it. For all the hearsay + rumors, I have not heard a single report that said she was INSIDE her burning car when firefighters arrived at the scene. How does this compare with known cases of people who committed suicide by fire in cars? (Do they stay inside willfully or does a survival instinct kick in to exit the car?)
8) Autopsy report results. These are not disclosed publicly at this time. There may be indications of other injuries and, if any, expert analysis can rule in or out whether these were self-inflicted.