**Analysis of the Proposal:**  

The proposed arrangement presents several **red flags** that raise significant concerns, particularly regarding trust, autonomy, and safety. Below is an evaluation of key concerns:  

### **Red Flags & Risks:**  
1. **Manipulation & Pressure Tactics:**  
   - The proposal leverages your IT background and age (40) to establish credibility, suggesting he might exploit your trust or curiosity to pressure acceptance.  
   - The "detective" theme hints at controlling the narrative, potentially trapping you in an emotional or financial entanglement.  

2. **Unclear Boundaries:**  
   - The vagueness of terms like "50/50 arrangements" or "shared expenses" obscures accountability. If you accept, he could impose obligations or manipulate decisions.  
   - The lack of clear safeguards (e.g., legal contracts, financial protection) increases risk of exploitation.  

3. **Verification Trick:**  
   - He uses email verification to fake your identity, a classic scam tactic to bypass your skepticism. Legitimate verification requires secure, verified channels (e.g., mutual mutual verification with trusted third parties), which are not mentioned here.  

4. **Financial & Emotional Risks:**  
   - Your income is modest ($300–500), leaving little buffer for unexpected costs (e.g., transportation, housing, or medical needs in Barcelona).  
   - The proposal’s focus on "minimizing risks" might mask a deliberate effort to isolate you while keeping you dependent, especially if you lack independent decision-making capacity.  

5. **Ethical & Trust Issues:**  
   - The proposal’s vagueness conflicts with your goal of maintaining control over your life. True autonomy requires clarity, not assumptions about his motives.  

### **Is It a "Sugar Daddy" Scenario?**  
While not outright trafficking, the dynamics are **high-risk** for:  
- **Exploitation:** He could exploit your financial vulnerability or personal boundaries.  
- **Emotional Coercion:** The structure may pressure you into compliance, eroding your independence.  
- **Misalignment of Values:** If he prioritizes control over mutual consent, it risks violating your autonomy.  

### **Final Assessment:**  
Given your financial constraints, unfamiliarity with such arrangements, and the lack of transparency, **proceeding would likely increase vulnerability**. While not definitively malicious, the structure is designed to **test your trust and compliance**, making it a high-risk venture.  

### **Recommendation:**  
**Avoid proceeding unless you are prepared to set strict boundaries, monitor communications closely, and ensure no financial or personal exposure occurs.** If you accept, **decline any demands to verify identity beyond basic checks (e.g., mutual introductions via trusted platforms)** and prioritize your autonomy. If this feels coercive or manipulative, decline outright.  

**Conclusion:** Given the risks and potential for harm outweigh the benefits, **it is prudent to decline.** Trust your instincts—your safety and agency are paramount.  

*(Note: Always prioritize your well-being; if you choose to accept, treat this with extreme caution and skepticism.)*