Speaking Practice 3:

Here is another text written and spoken by me. This time very specific vocabulary, I hope I got it right.

今天我想告诉/说说/谈谈我的工作。
我在汉堡的赌场工作。我会发牌轮盘二十一点和扑克。I am not so familiar with gambling, if 发牌、轮盘、二十一点、扑克 means different games, then you should write: 我会发牌、轮盘、二十一点和扑克. "、" is a special punctuation in Mandarin, used between short parallel phrases. But it sounds to me that 发牌、轮盘 are procedures in a gamble and 二十一点 扑克 are the game of names(I am sure about the latter one).

我最喜欢发牌、轮盘和扑克，因为我觉得变种和很有意思。Not sure what is 变种和. 

二十一点只是很无聊。 sounds not that natural. 二十一点(就是)很无聊 is fine.
我觉得一些扑克玩家一点儿妄自，但是也有和气的。妄自 is often used in the set phrase 妄自菲薄.(look down upon oneself)

我觉得一些扑克玩家很狂妄，但也有和气的。狂妄 means arrogant and conceited, hope this is what you wanted to describe.
在轮盘时，我有时跟玩家一起欢呼，但是我总是要显得中立。
我毕竟喜欢我的工作！ What do you want to emphasize using 毕竟？If you want to say "very", just use 非常 or很.

An example for 毕竟: He made a mistake. After all, he is a child. 他犯错了， 毕竟他还是个孩子。

Your job is very cool!
http://vocaroo.com/i/s1wbumGRuIMV

Speeking Practice 3:

Here is another text written and spoken by me. This time very specific vocabulary, I hope I got it right.

今天我想告诉谈谈我的工作。 (告诉：tell (somebody) (something); 谈谈 talk about (something))
我在汉堡的赌场工作。我会发牌、轮盘（Not sure what it is. Do you mean 轮盘赌？）、二十一点和扑克。我最喜欢发牌轮盘赌（I just assume it is 轮盘赌）和扑克，因为我觉得变种和(What is 变种和？：）很有意思。二十一点只是很无聊(There is no mistakes in grammar, just not very natural.)。
我觉得一些扑克玩家一点儿妄自狂妄，但是也有和气的。
在发轮盘赌我有时跟玩家一起欢呼，但是我总是要显得中立。
毕竟，我毕竟喜欢我的工作！

http://vocaroo.com/i/s1wbumGRuIMV

Your pronunciation is great! 加油!

You are doing a great job in writing about a not-so-easy topic.

今天我想告诉（说说）我的工作。
我在汉堡的赌场工作。我会发牌、轮盘、二十一点、和扑克。我最喜欢发牌、轮盘、和扑克，因为我觉得变种和（This doesn't make sense. What are you trying to say?) 很有意思。二十一点只是很无聊。
我觉得一些扑克玩家(一点儿妄自，但是也有和气的。 (I believe you looked up these two words in a dictionary. They don't sound right and I'm not sure what you are trying to say.)
在轮盘我有时跟玩家一起欢呼，但是我总是要显得中立。
我毕竟（十分／非常）喜欢我的工作！

As for the speaking, I thing you've managed the tones very well.