Your post has many vastly different questions...
Speed restrictions could relate to maintaining a max 18 degree bank limit on a specific turn radius, ie if you see a speed restriction on a specific turn such as 170kts, the radius design assumes an 18 degree bank limit with tailwinds.
Within the construction of your procedures and your understanding of regulations and how to fly the damm aircraft is it ALWAYS required to complete the 3rd and 4th segment when experiencing engine failure / designing a tailored procedure.
The second segment is the critical segment EO.
Are you combining EO and a tailored procedure? There are many different ways to look at this.
You cannot find EO in any design criteria because it does not exist.