Your dream contains several powerful themes and emotions that can be explored for deeper understanding.

1. Work and Responsibility: Your position as a vendor and the relocation of your display might symbolize feelings about your current job or responsibilities. The poor condition of the new display could suggest a sense of inadequacy or concern about how your work is perceived by others or how you perceive it yourself.
2. Conflict and Aggression: The urge to commit arson and the feelings of regret that followed could signify an internal struggle. It may reflect frustrations you have been feeling in your waking life—perhaps regarding your job, personal relationships, or feelings of being overwhelmed. The extreme action of wanting to harm others may symbolize a desire to express or release pent-up emotions or frustrations.
3. Fear of Consequences: The fear of being arrested and the reaction of your sister and coworkers indicate anxiety about how your actions might affect your relationships and reputation. This suggests that you might be grappling with guilt or fear of judgment in your waking life, feeling that your decisions could lead to negative consequences.
4. Isolation and Regret: Fleeing the scene and grieving your relationships highlight a sense of isolation and the emotional toll of your actions or thoughts. This may represent a fear of losing connections due to your behavior or choices, whether real or imagined.

Overall, this dream seems to be a reflection of your current emotional state, particularly regarding your responsibilities, frustrations, and fears of consequences in your life. It may be beneficial to explore these feelings in your waking life. Consider reflecting on any stressors or conflicts you're experiencing and how you might address them in a constructive way, rather than allowing them to manifest into harmful thoughts or actions.