I am a Canadian Registered Nurse who has her Florida License.  I would like to work seasonally in the state of Florida under TN status.  Am I able to leave Florida after working 6 months or less?  Would my husband and dependant children (under 21) need TD status?

I have stated before that Canadians seeking TN status are not required to work full-time.  However, this does not necessarily mean you that can obtain a one year TN, work full time for six months, and then leave the country for the rest of your authorized period of stay without having your status terminate.  However, there is no reason why you would want to do that.  You could simply seek a TN for six months, return to Canada for the next six months, and then apply for a new six month TN upon your re-entry to the United States.   

If your husband and dependent children are coming to the United States only six months out of every year (i.e. snowbirds), they could continue entering as B-2 tourists.  However, there is no reason why they would want to do that.  They would clearly be entitled to TD status while you are working in the United States, it could be obtained easily once you were approved for TN status, and as TD aliens they would be subjected to less scrutiny at the time of entry and would be able to attend school in the United States. 

I held H-1B status from 1992 to 1995.  I left the United States in 1995 and became a Landed Immigrant. After two months in Canada, I returned to the United States where I engaged in unauthorized employment.  However, I continued to visit Canada often.  I never stayed in the United States more than 180 days at a time during this period.  I now have permanent job offer as an engineer and my employer is willing to file for my permanent residence.  Am I barred from seeking permanent residence?  Can I use my unauthorized employment to show work experience for the labor certification and work authorization?  

If you review the applicable grounds of exclusion, you will see that previous illegal employment does not, in and of itself, bar you from permanent residence.  The ground of exclusion at INA §212(a)(5)(A) does not exclude aliens for previous unauthorized employment, only aliens seeking entry to engage in unlawful employment.  Periods of unlawful presence may result in three- or ten-year bar under INA §212(a)(9)(B)(i) but you indicated that you never stayed in the United States more than 180 days at a time; this would appear to preclude application of these bars.   However, there is one ground that may result in your exclusion from the United States.  Each time that you entered the United States, you had to tell the inspecting officer the purpose of your visit.  If you made any material misrepresentations in order to gain entry, you would be excludable under INA §212(a)(6)(C)(i). 

If you can establish that you were granted admission during the period of your unauthorized employment without your having made any material misrepresentations, you should be fine.  However, a consular officer (as you are have engaged in unlawful employment, you will be unable to adjust status in the United States) will tend to believe that you did make a material misrepresentation in this scenario, so be prepared for a difficult fight.  If you are unable to convince the consular officer that you did not make a material misrepresentation, you will not be able to immigrate to the United States unless you qualify for the limited waiver available under INA §212(i)(1). 

With regard to using this unlawful employment in your labor certification and immigrant petition, there appears to be nothing to prevent you from doing so.  Of course, you will be disclosing the unauthorized employment much earlier in the immigration process.  However, since you will eventually have to disclose it anyway, you are probably no worse off.    

I currently hold H-1B status.  Just before applying for the H-1B in Dec. 1998, I was arrested for a misdemeanor in the United States.  However, I have never been convicted, the misdemeanor charge was reduced to an infraction of disturbing the peace (no conviction just paying a fine ).  The attorney who got me out of this problem told me that, although I have not been convicted with a misdemeanor, the records will always show that I have been arrested for a misdemeanor since infractions can not be expunged.  I obtained my H-1B approval soon after.  However, since then I have been scared to leave the country to obtain an H-1B visa or to visit my family since the records show that I was arrested.  Is there a risk that the U.S. Consulate either in Canada or home will refuse to give me an entry visa because of this?

The first issue to determine is whether you have been "convicted."  I am not exactly sure what is meant by "infraction", but there probably was a conviction, at least for the purposes of immigration law.  Under INA §101(a)(48), the term "conviction" is now defined broadly as a formal judgment of guilt of the alien entered by a court or, if adjudication of guilt has been withheld, where:

1. a judge or jury has found the alien guilty or the alien has entered a plea of guilty or nolo contendere or has admitted sufficient facts to warrant a finding of guilt, and

2. the judge has ordered some form of punishment, penalty, or restraint on the alien's liberty to be imposed.

There does not appear to be ground of exclusion that would render you inadmissible for this offense.  According to 9 FAM §40.21(a) N2.3-2, the offense of disorderly conduct is normally not considered a crime of moral turpitude.  In light of this, I believe that your offense for "disturbing the peace" is probably not a crime of moral turpitude.  Accordingly, it would not be a ground of exclusion under INA §212(a)(2)(A)(i)(I)  or a ground of deportation under INA §237(a)(2)(A)(i) [crimes of moral turpitude].  Further, as you have been convicted of only one crime, you would not be excludable under INA §212(a)(2)(B) or deportable under INA §237(a)(2)(A)(i)(II) [multiple criminal convictions].  None of the other criminal grounds of exclusion or deportation appear to apply either.

You will definitely have to disclose the arrest on Form OF-156 when you apply for a visa.  Once it is disclosed, the consular officers will want to know everything that happened.  However, as stated above, a conviction for disorderly conduct should not be a ground of exclusion. 

I think that you should apply in Canada first, since you can still be readmitted under your H-1B without a visa in the event that your visa request is refused.  This is because you are entitled to automatic visa revalidation under 22 CFR §41.112(d) after a trip to continguous territory for less than thiry days.  If the post in Canada refuses you, you can still apply for the visa in your home country.  However, if you apply at your home country post first and are refused, you will be unable to apply at any other post.