5 Question about dedicated IP Address vs Shared IP address in Amazon SES

HI,

I have 5 question about Dedicated IP with Amazon SES:

1. Why exactly they recommend 2 dedicated IP? What happens if I start only with 1 IP? Can you give me some examples of the differences?

2. I understand that by default the warm-up is automatically, right? So, if I send to my list of 40,000 emails, 3 newsletters per week (120,000 emails per week), on each send of 40,000 the system automatically will send 1,000 emails from my new dedicate IP, and 39,000 from the shared IPs? That right? And it will increase the proportion on each send gradually.... but my main point here is... I don't have to do anything right?, I can continue with my normal sending, whole list, 3 times per week, and the system in the background will do the work to warm up gradually automatically? So, after this, we can continue with normal sending tactics.

3. For my sending: 3 times per week, 40k email, and maybe upgrading to 5 times per week gradually, is the best to have Dedicate IP vs not having?

4. My only problem that made me change shared IP to Dedicated Ip, it's that in Microsoft (Hotmail and Outlook), 100% of the email go to SPAM, and I don't know why... because same email sending from Active Campaing work perfect... This change to dedicate IP, will solve this? Or there is another way to solve this huge problem without change to dedicated IP?

5. If for any reaseon, the dedicated IP doesn't result well to my business, I can back to shared IP like now, and that change from Dedicated IP to Shared IP again, doesn't affect the deliverabily on any bad way?

Looking forward your replies,

Thanks in advance, Best regards,

Sebastian