Implementation Options: Server Side Object Model & Client Side Object Model

Hi All, I'm design a custom web application and it will be deploy on SharePoint 2010/2013 (to be confirmed) server, and I found some aritical as follows:

http://consultingblogs.emc.com/sanjaypatel/archive/2011/09/17/comparison-between-server-side-object-model-client-object-model-rest-api-s-and-decision-matrix-on-what-to-use-when.aspx

May I ask ask your advice for following items?

1) Is the above URL still valid? e.g. Vice Versa for SharePoint 2013?

2) Microsoft has a phase out plan for server side object model or not? (e.g. MOSS 202X)

3) For programmatcally update of SharePoint permission: should I call client-side OM instead of server-side OM even I will deploy the web application to SharePoint server?

Thank you very much.

.NET Beginner 3.5