It isn't. However, the non-past verb endings in second person singular are all spelt ешь, ёшь and ишь.
If a noun ends in a hush consonant (ш, ж, щ or ч), the final consonant is spelt with a soft sign if it's feminine (ночь, мышь, дрожь) and without a soft sign if the noun is masculine (луч, нож, овощ).
No. E.g. карандаш - a pencil. That said, all feminine nouns ending with ш get a soft sign: e.g. мышь - a mouse. Also, all 2nd person verbs ending with ш get a soft sign, which is relevant to this case. (And I think the only verbs that end with a ш sound are present tense, 2nd person.)