I've never used it but couldn't the urlRewriter in Umbraco work for you? Configure "/step2" to point to "/" (home in this case) ?

yeah, thanks for suggesting that, it works like a charm.

<rewrite>
  <rewriteMaps>
    <rewriteMap name="StaticRewrites">
      <add key="/step1" value="/" />
      <add key="/step2" value="/" />
      <add key="/step3" value="/" />
      <add key="/step4" value="/" />
      <add key="/summary" value="/" />
      <add key="/thankyou" value="/" />
    </rewriteMap>
  </rewriteMaps>
  <rules>
    <rule name="Rewrite Rule">
      <match url=".*" />
      <conditions>
        <add input="{StaticRewrites:{REQUEST_URI}}" pattern="(.+)" />
      </conditions>
      <action type="Rewrite" url="{C:1}" />
    </rule>
    <rule name="Remove trailing slash" stopProcessing="true">
      <match url="(.*)/$" />
      <conditions>
        <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
        <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
      </conditions>
      <action type="Redirect" redirectType="Permanent" url="{R:1}" />
    </rule>
  </rules>
</rewrite>

Also I found this quite useful - redirect to HTTPS, if release configuration (you should put it to Web.Release.config) for automatic transformation.

<system.webServer>
<rewrite >
  <rules>
    <rule name="HTTP to HTTPS redirect" stopProcessing="true" xdt:Transform="Insert">
      <match url="(.*)" />
      <conditions>
        <add input="{HTTPS}" pattern="off" ignoreCase="true" />
        <add input="{HTTP_HOST}" pattern="localhost" negate="true" />
      </conditions>
      <action type="Redirect" url="https://{HTTP_HOST}/{R:1}" redirectType="Permanent" />
    </rule>
  </rules>
</rewrite>

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