problem with historical data

[jackee1234]

1. I use the history center to download the 15 mins time frame, but it can download until 2014, what should I do if I need more data?

2. This page (https://www.mql5.com/en/forum/124322) mentions that 

"The metaquotes "download" data is really to be avoided at all costs in my opinion, loaded with spurious ticks, bad candles, and missing candle gaps all over the place."

 Is it true? If yes how to get the good data? 

3. The following 4 hour chart jumps from 25 Nov to 30 Dec in metatrader, what's the problem? Is it because of question 2?