Need help configuring ELK to receive logs from log4net/udpappender

Elastic Stack Kibana
3

here's the output:

# curl -XGET 'localhost:9200/_cat/indices/*?v&s=index&pretty'
health status index               pri rep docs.count docs.deleted store.size pri.store.size
yellow open   logstash-2017.06.09   5   1          3            0     14.7kb         14.7kb
yellow open   .kibana               1   1          2            0      8.3kb          8.3kb
yellow open   logstash-2017.06.08   5   1        419            0      150kb          150kb

When I started this post I was only getting .kibana index.. I left it on overnight and now I see these other two indexes as well.. Also now the @timestamp options shows up under indices tab in Kibana and I can see the hearbeat logs too which I have configured in the /etc/logstash/conf.d/logstash.conf file. These heartbeat log come every 10 seconds, but Kibana only shows them after 4 hours.
If I select
Last 15 minutes Last 30 minutes Last 1 hour
under Discover tab, nothing shows up. is there some setting to change that, to show latest logs, every second ??

Also, Time stamp in Kibana is 5 hours ahead of the Central time we follow.

{
       "message" => "2017-06-09 05:02:16,751 [30] DEBUG - WS206 - ApplicationName - someapp.Logging.someappLogger - REQ_END POST: /api/client/reportbuilder/getReportFilterValueData  [200, 49 ms]\r\n",
      "@version" => "1",
    "@timestamp" => "2017-06-09T10:00:39.902Z",
          "type" => "log4net",
          "host" => "192.168.x.xxx",
          "tags" => [
        [0] "_grokparsefailure"
    ]
}
{
       "message" => "2017-06-09 05:02:19,270 [48] DEBUG - WS206 - ApplicationName - someapp.Logging.someappLogger - REQ_START POST: /api/client/reportbuilder/getReportFilterValueData \r\n",
      "@version" => "1",
    "@timestamp" => "2017-06-09T10:00:42.422Z",
          "type" => "log4net",
          "host" => "192.168.x.xxx",
          "tags" => [
        [0] "_grokparsefailure"
    ]
}

I have started getting the Logs from Visual studio UdpAppender on Logstash and Kibana. The logs are like above, My filter is as shown in the main post at the top of this page.

Couple of issues, Logging time and actual time of the log generated is different (I guess ELK follows UTC and our application logs follow central time), how do I fix that??

All of our logs will be mostly around Exceptions received from Visual studio/IIS servers/asp .net applications and web apps. What is the best filter for these logs??

What to do with the [0] "_grokparsefailure"