web.config changes for KB3159706 - powershell

Question

i spent a few hours trying to code this by myself, but i don't know much about editing the web.config and all the examples i found don't come close to what i need. CHANGE#1 is unique because it does include the typical key=value.
I want to be able to script (PowerShell) the required modifications of Web.Config, only if the values do not already exist.
CHANGE#1:
Onsert this
(if not already there and "true"): multipleSiteBindingsEnabled="true"
<serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true"/>
CHANGE#2:
Insert this if not already there:
<endpoint address=""
binding="basicHttpBinding"
bindingConfiguration="SSL"
contract="Microsoft.UpdateServices.Internal.IClientWebService" />
<endpoint address="secured"
binding="basicHttpBinding"
bindingConfiguration="SSL"
contract="Microsoft.UpdateServices.Internal.IClientWebService" />
It goes between here:
<services>
<service
name="Microsoft.UpdateServices.Internal.Client"
behaviorConfiguration="ClientWebServiceBehaviour">
<!-- ... CODE FROM CHANGE#2 GOES HERE ... -->
</service>
</services>
This is the code so far for change#1 (not working):
$sWSUSwebConfig = "C:\Program Files\Update Services\WebServices\ClientWebService\Web.Config"
$xFileContent = [Xml](Get-Content $sWSUSwebConfig)
$root = $xFileContent.get_DocumentElement()
foreach ($item in $root."system.serviceModel"."serviceHostingEnvironment") {
if ($item."multipleSiteBindingsEnabled" -ine "true") {
$activeConnection = $root.serviceHostingEnvironment
$activeConnection.SetAttribute("multipleSiteBindingsEnabled", "true")
#$item.add."multipleSiteBindingsEnabled" = "true"
$iKeyFound = $true
}
}
$xFileContent.Save("c:\temp\web.config")
Reference for modifications: step 3 from kb3159706.