I don't see any reason these words (or combination of letters) should be censored in Japanese language. To my full imagination, there are no slang, rhyme, abbreviation or metaphor that makes these phrases offensive.
In an unofficial wiki of the game, they list some of the words/phrases that are sensored in the in-game chat. The writer seems to agree with us; the description starts with "There are oddly many 伏字 (censoring with **), which sometimes makes the chat incomprehensible".
Anyway, to read the article---
- Some of the words are understandable as vulgar or violent; 殺す (to kill), ﾀﾋ (as in 死) etc.
- Many words that can (ever) have political meanings are also censored; nations' names, 自由 freedom, etc.
- Others includes those which are fine in Japanese, but seem to be censored in terms of Chinese language or government; "89", the kanji "操" (accordning to the wiki, it's a part of insulting phrase in Chinese).
- However, many others are still very puzzling; "ri" (only in lower case), "コン", "ssa", "合成" to name a few.
Apparently the censorship is conducted in a least sophisticated way (see Scunthorpe problem as suggested by @conman). It is also apparent that the administrators are very sensitive to any word they come up with. However, these words or parts in your examples have no problem in Japanese: they are false-positives.