It is not permitted for the person during the state of i'tikaf to smell fragrance with enjoyment. Based on an obligatory precaution a person during the state of i'tikaf should completely avoid all kinds of fragrance. If the use of toothpaste causes this, one should refrain from it; if it does not then it is permissible.
It is recommended to greet all Muslims whether they were practicing or not. It is better to offer help to believers whether they were practicing or not. Also it is better to socialize with people in good manner with people who practice Islam and with the ones that do not. It appears in some of the narrations that the good behavior deserves great reward.