Some words that have the second letter U are:augustaurabullbutchercuddlecutdunedurableeuphemismEuropefullfungungutterhurlhutjudgejumpjuryjustkudoslunchluremuchmudmullmurdernudgenullnuptialouchouroutpuddingpunchpushquailquarryquartquartzquoteruderuinrulerushruthlesssuddensuitsullensuppersuretunneltummyturkeyvulnerablevulture
canalcaratfatalJapanKansaskaratkayakmacawmadamnavalpaganradarsalad
okra
khaki
autos, butte, cutie, futon, outer, tutor
Some five letter words with a second letter U are:audioauditaugerbuddybudgebuglebuildbulgebulkybullybunchbuncobunnyburntburroburstbushybutch,buttebuxombuyercubiccumincupidcuriocurlycursecurveduchyduckydummy,dumpydunceduskydustyduvetfudgefuguefumesfunkyfunnyfurryfussyfutonfuzzyguardguavaguessguestguideguildguiltguisegulaggulchgumbogummyguppygustygutsyhubbyhuffyhumanhumidhumorhumushunchhungerhunkyhurryhuskyhussyhutchjudgejuicejulepjumbojumpyjurorkudoskudzulucidluckylucrelumpylunchluridlustymucusmuddymuggymulchmunchmuralmurkymushymusicmuskymustysully,sunny,
The words with the form _L_O are also, alto, and oleo/olio.
Some four letter words with a second letter U are:auraburncurbcuredulldumbeurofundguruhugejumpjunklumpluremuchmutenudeoustpullpurepushrulerumpruinruserushrustsuchsurftune
Some three letter words with the second letter W are:awleweoweowlowntwo
No answer yet, but it probably ends with "ing"
Forty Love
Some six letter words with p as the second letter are opener, operas, sparse, and apiece.