1) I picked the Roth style 401K because I imagine taxes will rise in the future but I've also heard an argument about being in a lower tax bracket when older. On do not own a home but plan to purchase one in the future if 401K can be borrowed against or used as any type of collateral. Any preferences between the regular 401K and Roth 401K?
The main thing to consider is whether your own personal tax bracket will be higher now or when you retire. If you expect your own personal tax rate to be higher in retirement, Roth accounts are better. If you expect your tax rate to go down, traditional accounts are better.
Keep in mind that if you retire with 100% of your savings in Roth accounts, none of that money will count as income when you withdraw it, so you'll pay 0% tax in retirement. If your tax bracket is higher than 0% right now, a traditional 401(k) would be a better idea in this situation.
2) I've diversified into 5 difference funds. 10% goes to 4 of them and 50% goes to a Large Cap Growth Fund. Fees range from $5.90 to $10.30 per $1,000. There's not too much money going into all of these so is this too much diversification, too little, or just right? Do those fees seem high given the amount of money I'll be contributing?
What are the funds you're buying? Buying lots of different funds does not necessarily mean you'll be more diversified if the funds are invested in mostly the same thing (five different US stock funds, for example). Diversify across asset classes. Decide what percentage of your money you want in stocks, what percentage you want in bonds, and what percentage of each of these you want in US versus international assets. Once you have decided this, try to find one fund with low fees that invests in that type of assets.
These fees on your funds aren't completely outrageous, but they are on the high side. Do you have any funds available that charge less than 0.5% ($5.00 per $1,000)? What are they?
3) Should I try to go even higher than 20% of my pay or any opinions about adjusting it depending on my financial needs?
Take a look at MDM's list (copied below) for a good basic priority for where you should put extra money beyond what you need to pay for basic expenses:
WHAT
0. Establish an emergency fund to your satisfaction
1. Contribute to 401k up to any company match
2. Pay off any debts with interest rates ~5% or more above the 10-year Treasury note yield.
3. Max HSA
4. Max Roth or Traditional IRA based on income level
5. Max 401k (if 401k fees are lower than available in an IRA, swap #4 and #5)
6. Fund mega backdoor Roth if applicable
7. Pay off any debts with interest rates ~3% or more above the 10-year Treasury note yield.
8. Invest in a taxable account with any extra.
WHY
0. Give yourself at least enough buffer to avoid worries about bouncing checks
1. Company match rates are likely the highest percent return you can get on your money
2. When the guaranteed return is this high, take it.
3. HSA funds are totally tax free when used for medical expenses, making the HSA better than either traditional or Roth IRAs.
4. Rule of thumb: trad if current marginal rate is 25% or higher; Roth if 10% or lower; flip a coin in between
5. See #4 for choice of traditional or Roth for 401k
6. Applicability depends on the rules for the specific 401k
7. Again, take the risk-free return if high enough
8. Because earnings, even if taxed, are beneficial
Everyone's situation is different, but this is a good general guideline. Based on the high fees in your 401(k), you may want to start out with whatever contribution you need to get the maximum match, then contribute to an IRA where you can get some cheaper investments, and then if you still have money left to save you can increase your 401(k) contributions.
Good luck!