You can combo from step kick but you have a very good options after it, if it is blocked you can do a hp.srk cancel it into full U1 or mp.srk for damage or cr.hk for a hard knockdown, you can also do a kara throw if the rival expect a srk… so it is an awesome move as you see.
Ken is not bad poking so use it, also, you can combo almost everything from a cr.lk, some options are (optinal) :
cr.lk, cr.lp, (cr.lp), hp.srk
cr.lk, cr.lp, cr.hp, tatsu (ex tatsu)
cr.lk, cr.lp, cr.hp, srk (ex srk)
cr.lk, cr.lp, cr.lp, hp.srk, FADC, (air ex tatsu), U1 (it is really unnecessary do the air ex tatsu but looks very good 
cr.lk, cr.lp, cr.mk, hadoken, FADC, U2
…
Really Ken has a lot of options, and a lot of combos.
One of the best things is the kara throw, with it you can throw farther and make people fear it so you can do it or try to go for a CH so in a block string…
cr.lk, cr.lp, kara.throw
or
cr.lk, cr.lp, cr.mp
or
cr.lk, cr.lp, (nothing)
or even
cr.lk, cr.lp, delay, hp.srk (CH) -> FADC U1
as you see it makes a lot of dangerous things 