Looks like it's working

assets/javascripts/discourse/components/query-result.js.es6

@@ -4,6 +4,7 @@ const Escape = Handlebars.Utils.escapeExpression;
 
 import avatarTemplate from 'discourse/lib/avatar-template';
 import { categoryLinkHTML } from 'discourse/helpers/category-link';
+import Badge from 'discourse/models/badge';
 
 var defaultFallback = function(buffer, content, defaultRender) { defaultRender(buffer, content); };
 
@@ -16,10 +17,14 @@ function randomIdShort() {
   });
 }
 
-function transformedRelTable(table) {
+function transformedRelTable(table, modelClass) {
   const result = {};
   table.forEach(function(item) {
-    result[item.id] = item;
+    if (modelClass) {
+      result[item.id] = modelClass.create(item);
+    } else {
+      result[item.id] = item;
+    }
   });
   return result;
 }
@@ -87,10 +92,32 @@ const QueryResultComponent = Ember.Component.extend({
   transformedUserTable: function() {
     return transformedRelTable(this.get('content.relations.user'));
   }.property('content.relations.user'),
+  transformedBadgeTable: function() {
+    return transformedRelTable(this.get('content.relations.badge'), Badge);
+  }.property('content.relations.badge'),
+  transformedPostTable: function() {
+    return transformedRelTable(this.get('content.relations.post'));
+  }.property('content.relations.post'),
+  transformedTopicTable: function() {
+    return transformedRelTable(this.get('content.relations.topic'));
+  }.property('content.relations.topic'),
 
-  lookupUser: function(id) {
+  lookupUser(id) {
     return this.get('transformedUserTable')[id];
   },
+  lookupBadge(id) {
+    return this.get('transformedBadgeTable')[id];
+  },
+  lookupPost(id) {
+    return this.get('transformedPostTable')[id];
+  },
+  lookupTopic(id) {
+    return this.get('transformedTopicTable')[id];
+  },
+
+  lookupCategory(id) {
+    return this.site.get('categoriesById')[id];
+  },
 
   downloadResult(format) {
     // Create a frame to submit the form in (?)

assets/javascripts/discourse/components/query-row-content.js.es6

@@ -1,5 +1,29 @@
 import binarySearch from 'discourse/plugins/discourse-data-explorer/discourse/lib/binary-search';
+import avatarTemplate from 'discourse/lib/avatar-template';
 
+function icon_or_image_replacement(str, ctx) {
+  str = Ember.get(ctx.contexts[0], str);
+  if (Ember.isEmpty(str)) { return ""; }
+
+  if (str.indexOf('fa-') === 0) {
+    return new Handlebars.SafeString("<i class='fa " + str + "'></i>");
+  } else {
+    return new Handlebars.SafeString("<img src='" + str + "'>");
+  }
+}
+
+function shorthandTinyAvatar(username, uploadId, ctx) {
+  username = Ember.get(ctx.contexts[0], username);
+  uploadId = Ember.get(ctx.contexts[0], uploadId);
+  return new Handlebars.SafeString(Discourse.Utilities.avatarImg({
+    size: "tiny",
+    extraClasses: '',
+    title: username,
+    avatarTemplate: avatarTemplate(username, uploadId)
+  }));
+}
+
+const esc = Handlebars.Utils.escapeExpression;
 
 const QueryRowContentComponent = Ember.Component.extend({
   tagName: "tr",
@@ -12,18 +36,29 @@ const QueryRowContentComponent = Ember.Component.extend({
     const self = this;
     const row = this.get('row');
     const relations = this.get('extra.relations');
+    const parent = self.get('parent');
 
     const parts = this.get('columnTemplates').map(function(t, idx) {
-      const params = {};
+      const ctx = {};
+      const params = {}
       if (t.name === "text") {
-        return row[idx];
+        return esc(row[idx]);
       } else if (t.name === "user") {
-        params.user = self.get('parent').lookupUser(parseInt(row[idx]));
+        ctx.user = parent.lookupUser(parseInt(row[idx]));
+        if (!ctx.user) {
+          return esc(row[idx]);
+        }
+      } else if (t.name === "badge") {
+        ctx.badge = parent.lookupBadge(parseInt(row[idx]));
+        params.helpers = {"icon-or-image": icon_or_image_replacement};
+      } else if (t.name === "post") {
+        ctx.post = parent.lookupPost(parseInt(row[idx]));
+        params.helpers = {avatar: shorthandTinyAvatar};
       } else {
-        params.value = row[idx];
+        ctx.value = row[idx];
       }
 
-      return new Handlebars.SafeString(t.template(params));
+      return new Handlebars.SafeString(t.template(ctx, params));
     });
 
     buffer.push("<td>" + parts.join("</td><td>") + "</td>");

assets/javascripts/discourse/templates/explorer/badge.raw.hbs

@@ -0,0 +1,2 @@
+{{! source: badge-button component }}
+<span class="user-badge {{badge.badgeTypeClassName}}" title="{{badge.displayDescription}}" data-badge-name="{{badge.name}}">{{icon-or-image badge.icon}} <span class="badge-display-name">{{badge.displayName}}</span></span>

assets/javascripts/discourse/templates/explorer/post.raw.hbs

@@ -0,0 +1,4 @@
+<aside class="quote" data-post="{{post.post_number}}" data-topic="{{post.topic_id}}"><div class="title" style="cursor: pointer;">
+  <div class="quote-controls">{{!<i class="fa fa-chevron-down" title="expand/collapse"></i>}}<a href="/t/via-quote/{{post.topic_id}}/{{post.post_number}}" title="go to the quoted post" class="quote-other-topic"></a></div>
+  {{avatar post.username post.uploaded_avatar_id}}{{post.username}}:</div>
+  <blockquote><p>{{{post.excerpt}}}</p></blockquote></aside>

assets/javascripts/discourse/templates/explorer/user.raw.hbs

@@ -1,5 +1 @@
-{{#if user}}
-  <a href="/users/{{user.username}}/activity">{{avatar user imageSize="tiny"}} {{user.username}}</a>
-{{else}}
-  User #{{value}} (deleted)
-{{/if}}
+<a href="/users/{{user.username}}/activity">{{avatar user imageSize="tiny"}} {{user.username}}</a>

plugin.rb

@@ -41,9 +41,6 @@ after_initialize do
 
     class SmallBadgeSerializer < ApplicationSerializer
       attributes :id, :name, :badge_type, :description, :icon
-      def badge_type
-        object.badge_type.name
-      end
     end
 
     class SmallPostWithExcerptSerializer < ApplicationSerializer