What are the answers to the Boss's ciphers?

1. The numbers represent alphabets, where A is 1, B is 2 and so on.
2. Take the letter's position in the alphabet, add 8 and take that letter instead. (A becomes I, Y becomes G and so on)
3. Type in the code, but shift your hands one key to the left. (Instead of O, press I and so on. Only works on qwerty keyboard though.)
4. It's a base64-encoded string, use a base64-decoder for that.

First answer:

master branch

Second answer:

there is a treasure hidden somewhere, it is located at a secret place in the pacific ocean

Third answer:

in a world full of blocks

Fourth answer:

the plant is famous because of the ability to cure some diseases

I've only worked out two so far. I'm not sure if the message is the same so I'll just post my method.

1. This is a simple number substitution cipher. Replace the letters with their appropriate number in the alphabet (1-A, 2-B, 3-C, etc.)
2. This one is a typical ROT cipher, ROT -8 to be exact. Use this page to decrypt your message. I already put in the setting.
3. The ; characters give the hint here - you need to transpose each letter on the keyboard (one to the left), on a standard QWERTY keyboard.
4. The fourth message is Base64 encoded.

For the fifth and the hardest one:

This is called "Rail Fence cipher". It writes out the original texts in 3 rows in a "zig-zag" manner. For example, the message EXAMPLE would be written as:

E . . . P . . 
. X . M . L . 
. . A . . . E

Then we will read it one row at a time, left to right:

EP
XML
AE

Thus, the cipher would be: EPXMLAE.

Now, for question 5. Do the rail fence cipher, THREE TIMES!

the gold factory was built long time ago, and it is the most famous gold factory in the world (original message)

t---g--- ---t--- --- ---l---o---t--- ---,---d--- ---t---m--- ---o---g--- ---t--- ---t---w---d
-h- -o-d-f-c-o-y-w-s-b-i-t-l-n- -i-e-a-o- -n- -t-i- -h- -o-t-f-m-u- -o-d-f-c-o-y-i- -h- -o-l-
--e---l---a---r---a---u--- ---g---m---g---a---i---s---e---s---a---s---l---a---r---n---e---r---

tg t lot ,d tm og t twdh odfcoywsbitln ieao n ti h otfmu odfcoyi h olelarau gmgaisesaslarner

t--- ---t--- ---o--- ---h---f---w---t---i--- ---i---o---u---f---i---o---a--- ---a---s---a---r
-g-t- -o- -d-t- -g-t-t-d- -d-c-y-s-i-l- -e-o-n-t- - -t-m- -d-c-y- - -l-l-r-u-g-g-i-e-a-l-r-e-
-- ---l---,---m--- ---w---o---o---b---n---a--- ---h---f---o---o---h---e---a---m---s---s---n--

t t o hfwti ioufioa asargt o dt gttd dcysil eont tm dcy llruggiealre l,m woobna hfooheamssn

t---o---w---i---i---a---g--- ---g--- ---s---e--- --- --- ---r---i---r---,---o---a---o---a---n
- - - -f-t- -o-f-o- -s-r-t-o-d- -t-d-d-y-i- -o-t- -m-d-y- -l-u-g-e-l-e-l-m-w-o-n- -f-o-e-m-s-
--t---h---i---u---a---a--- ---t---t---c---l---n---t---c---l---g---a--- --- ---b---h---h---s--

towiiag g se rir,oaoan ft ofo srtod tddyi ot mdy lugelelmwon foemsthiuaa ttclntclga bhhs (cipher in question)