Yes, I think that does indeed illustrate the problem!
What phone and OS version are you using? Have you tried a different keyboard application? And are you having any other problems, e.g. with the touchscreen?
Using a Galaxy Note 2 with 4.1.1 The above post was written in Firefox, and I tried using a couple of keyboards. Mostly written using Kii beta, but also using Hacker's Keyboard and the stock keyboard with no apparent difference.
I'm now back on my laptop, so hopefully I can explain this in a more complete way. There are a couple of different things going on, and I'm not sure how related they are.
1) The post above is unusual, not sure exactly what was going on there, except that when I started writing the post the last word of the title would start in the body of the email, and then later when writing words would occasionally be written both where my cursor was placed and at the beginning of the post at the same time, trying to delete the text at the top of the post would get things even more screwed up. This seemed to be some obvious bug that I assume is either Firefox related or this forum related, or some combination of the both.
2) My more generic complaint is that I have a ton of trouble highlighting a bunch of text that I want to delete. I feel like I should be able to tap and drag to highlight text, but that doesn't work. Instead I tap and hold, and sometimes (but only maybe1 out of every 3 times I try) I'll get one word highlighted with the handles that theoretically you can drag to highlight everything else you want to delete. This almost never works though, I'll grab the left handle because I want to move left, and immediately it seems to turn into the right handle. It's hard for me to really explain what seems to be going on, except to say that I almost always give up and decide it's faster just to use the backspace key to delete pages of text, rather than trying to highlight it. If I need to copy it I can either use Hacker's keyboard, which makes it possible to use Ctrl+A to select all or else I just give up after 10 minutes and decide it can wait until I'm at a real computer. Either way it is incredibly frustrating for something I consider one of the most essential functions of any computer (seriously, it was easier to copy text in DOS than it is on my Note 2).