if you do add a little fan make sure they don't dry out as they will dry out faster than they have been so far.
i do not mind at all if the tomatoes get a bit scraggly leggy as we bury them so deep when planting that they will toughen up after they get planted out. in all of the years of planting tomatoes from starts (we have someone else grow them for us at their greenhouse) i don't think we've lost any at all using this method. i always pick the tallest ones at the greenhouse that look the best.
peppers on the other hand, yes, they will probably benefit from the small oscillating fan treatment. i would put it on a timer to make sure it comes on and off and doesn't just stay on all the time. we have also not lost many of these through the years of planting them out, including a few that i thought for sure were goners because some animal chewed through them. they eventually grew or resprouted. if this ever happens to you and you are short on space don't bother trying to recover the plant, it is actually better to just get another plant and put it in if you can. the time lost in regrowing will affect the crop coming along (especially if you have a shorter season). you can take the damaged plant and move it to a big pot to bring in towards fall if you would like to get something from it.
a few other things come to mind regarding tomatoes:
if you are only using peat pellets for starting the seeds they may just not be getting enough of the basic nutrients to the plant. after the first week add just a very very weak solution of a balanced fertilizer to the water when you water and see if that helps. some other plants with larger seeds get enough energy from the seeds that they do ok for a bit without much additional nutrients from the soil. so if they land in poor soil they will do ok at first and then just sit there.
also remember that the plant may be doing things with the root growth before doing much else. what you may think of as stalling is just laying the groundwork for what comes next.