Welcome to the Q&A Forum

Did you decide on a platform yet?  this was posted months ago, and was curious to your decision.  Other mozers are recommending Shopify.  I"m a WP girl myself, so I lean that way.  Just curious as to the final verdict.

When researching TTFB slowness for WORDPRESS I always start here:

https://varvy.com/pagespeed/ttfb.html

It's a great illustration on things you can control (beyond server) and I use it as a checklist ... I always seem to forget something simple.... like an edit in .htaccess.

IMHO, if somebody is paying us for SEO, then our GOAL is to get the homepage to load in a second or less.... especially if most of the users are mobile.  If it's mid 1 second, then we can grudgingly live with that.

I'm glad you asked about server response times.... for most sites, after the content is optimized ( smaller images, clunky code, etc...) the initial server response time is usually the culprit for getting over a second.... as long as the rest of the home page is "light".  Light to us is under 1MB.  Depending on your CMS, there are a variety of ways to get the response time to be 200ms or less.

Google Pagespeed, as David said, is a good measurement, but it's not the holy grail of measurements.  We use it only to identify areas that need improvement.  Waterfalls tell us what's taking so long and what's heavy.

You didn't ask about plugins - which is a major culprit to caching, minify errors, conflicts, speed and weight.  We limit all active plugins to TEN (including caching, SEO, security).  For some sites, plugin clean up is the easiest way to speed up a site.

At the end of the day, nothing beats clean code, light images and a lightening fast server.

I did this on my wordpress site.  Here are my instructions:

https://moz.com/community/q/switched-from-wix-to-wordpress-dreaded-hashtag-url

I'm in the same boat, and even tried the DRIVERS GARAGE solution (which is also posted on quite a few other blog sites).  Unfortunately, that did not work for me.  Neither did the REDIRECTION WP plugin, nor did editing my .htaccess a zillion different ways.  Heck, I even tried creating directories and html files with embedded java.

Here is the only redirection that DID WORK for me (as indicated it would by Peter):

JAVASCRIPT

(1) Create a Javascript file with this code:

var hashesarr = { "#!old-news/chi3":'/new-page/', 
"#!another-news/dkc8":'/another-new-page/', 
"#!something-old/eckje8":'/something-new/' };
for (var hash in hashesarr) {
var patt = new RegExp(hash);
if (window.location.hash.match(patt) !== null) {
window.location.href = hashesarr[hash]; 
} 
}

(2) Save that file to your theme's child folder (so it doesn't get overwritten in the future by theme or Wordpress updates.
I saved my file here: \wp-content\themes\aweseometheme-child\

(3) In your SEO Plugin, or wherever you can edit the home page's HEAD file, add this code:

(4) Test, make changes, try again and PRESTO!

As a disclaimer, I have not yet tested to see how this will affect SEO Pagerank or Google redirects.  I'm guessing I will still have to implement the Sitemap with the UGLY url's per the DRIVERS GARAGE.  But all my client really cared about was that the client's who bookmarked specific pages, or had links pointing to deep pages would be redirected properly.

MY AHA ANSWER WAS FOUND HERE:
http://www.simosh.com/article/cbgaifec-301-redirect-from-wix-to-wordpress.html
(Alex Nikitenko is a genious!)

AND JAVASCRIPT INSTRUCTION HERE:
https://codex.wordpress.org/Using_Javascript

I think you have misunderstood what I meant about the site.  The realtor site uses an IDX providor to manage their listings and custom searches.  HOWEVER, all the blogging, neighborhood info, and SEO relevant items remain on the main website.  But to look at a listing, or open a search, you have to LINK OUT to a customized page on the IDX server.  Most realtors in our area, who are ranking well, are utilizing a similar format.

I have a client with a realtor site that uses IDX for the listings feed.  We have several external links going over to the IDX site for various live custom searches (ie: luxury listings, waterfront listings, etc...).  We are getting a Moz spam ranking of 2/7 for both "Large Number of External Links" and "External Links in Navigation".  Chances are, these are related.

My question is this:

(1) Being the score is only 2/7, should I bother with fixing this?

(2) If I add a rel="nofollow" to all the site-wide links (in header, footer & menu) will this help?  I couldn't find anything definitive in the Q&A search.

Looking forward to any insights!!!