position of adverbs

In "wǒ zhǐ huì shuō yìdiǎnr", zhi occurs before the verb, even though it qualifies yidianr.  But in "wo xuixi hanyu yijing yige yue le", yijing occurs after the verb, even though it qualifies yige yue.  Would it be OK to put yijing before xuixi, parallel to the sentence with "zhi"?  

Well, in the sentence "wǒ zhǐ huì shuō yìdiǎnr", I would argue that "zhǐ" is modifying "huì" - am able to - and the object of that verb is "shuō yìdiǎnr".  In fact, "yìdiǎnr" is modifying "shuō".

The sentence "wo xuixi hanyu yijing yige yue le", I would also argue that "yijing" is modifying this noun clause "yi ge yue" so it may really be an adjective.

We can have fun all day attempting to discuss elements of Chinese grammar using English concepts but one thing I have learned over the years is that Chinese grammar is completely different with its own set of rules.

Placing Yǐjīng 已经 in front of xuéxí 学习 would actually be up to the speaker and wouldn't change the meaning of the sentence.