But as a newbie to Domoticz and RPi, I wonder what is the best approach to get this data to the RPi?
Can it be done via ethernet, via the Arduino connected via USB to the RPi?
I have no clue, so any help in the right direction is appreciated!
A wealth of information available...

Field byte byte Description
1 5 8 * Wind Speed (0.1kph)
2 9 12 * Current Wind Direction (0-255)
3 13 16 5 minute Wind Speed Peak (0.1 kph)
4 17 20 5 minute Wind Direction Peak (0-255)
5 21 24 Wind Chill (0.1 deg F)
6 25 28 Outdoor Temp (0.1deg F) (’97 and later)
7 29 32 Rain Total for today (0.01 in.)
8 33 36 Barometer (0.1 mbar)
9 37 40 Barometer 3-Hour Pressure Change (0.1 mbar)
10 41 44 Barometer Correction Factor(LSW)
11 45 48 Barometer Correction Factor(MSW)
12 49 52 Indoor Temp (0.1 deg F)
13 53 56 Outdoor Humidity (.1%)
14 57 60 Indoor Humidity (.1%)
15 61 64 Dew Point (0.1 deg F)
16 65 68 Date (day of year)
17 69 72 Time (minute of day)
18 73 76 Today's Low Chill Value
19 77 80 Today's Low Chill Time
20 81 84 Yesterday's Low Chill Value
21 85 88 Yesterday's Low Chill Time
22 89 92 Long Term Low Chill Value
23 93 96 Long Term Low Chill Date
24 97 100 Long Term Low Chill Time
25 101 104 Today's Low Outdoor Temp Value
26 105 108 Today's Low Outdoor Temp Time
27 109 112 Yesterday's Low Outdoor Temp Value
28 113 116 Yesterday's Low Outdoor Temp Time
29 117 120 Long Term Low Outdoor Temp Value
30 121 124 Long Term Low Outdoor Temp Date
31 125 128 Long Term Low Outdoor Temp Time
34 137 140 * Wind Speed (0.1kph)
35 141 144 * Current Wind Direction (0-255)
32 129 132 Today's Low Barometer Value
33 133 136 Today's Low Barometer Time
36 145 148 Yesterday's Low Barometer Value
37 149 152 Yesterday's Low Barometer Time
38 153 156 Long Term Low Barometer Value
39 157 160 Long Term Low Barometer Date
40 161 164 Long Term Low Barometer Time
41 165 168 Today's Low Indoor Temp Value
42 169 172 Today's Low Indoor Temp Time
43 173 176 Yesterday's Low Indoor Temp Value
44 177 180 Yesterday's Low Indoor Temp Time
45 181 184 Long Term Low Indoor Temp Value
46 185 188 Long Term Low Indoor Temp Date
47 189 192 Long Term Low Indoor Temp Time
48 193 196 Today's Low Outdoor Humidity Value
49 197 200 Today's Low Outdoor Humidity Time
50 201 204 Yesterday's Low Outdoor Humidity Value
51 205 208 Yesterday's Low Outdoor Humidity Time
52 209 212 Long Term Low Outdoor Humidity Value
53 213 216 Long Term Low Outdoor Humidity Date
54 217 220 Long Term Low Outdoor Humidity Time
55 221 224 Today's Low Indoor Humidity Value
56 225 228 Today's Low Indoor Humidity Time
57 229 232 Yesterday's Low Indoor Humidity Value
58 233 236 Yesterday's Low Indoor Humidity Time
59 237 240 Long Term Low Indoor Humidity Value
60 241 244 Long Term Low Indoor Humidity Date
61 245 248 Long Term Low Indoor Humidity Time
62 249 252 Today's High Wind Speed Value
63 253 256 Today's High Wind Speed Time
64 257 260 Yesterday's High Wind Speed Value
65 261 264 Yesterday's High Wind Speed Time
66 265 268 Long Term High Wind Speed Value
67 269 272 Long Term High Wind Speed Date
68 273 276 Long Term High Wind Speed Time
71 285 288 * Wind Speed (0.1kph)
72 289 292 * Current Wind Direction (0-255)
69 277 280 Today's High Outdoor Temp Value
70 281 284 Today's High Outdoor Temp Time
73 293 296 Yesterday's High Outdoor Temp Value
74 297 300 Yesterday's High Outdoor Temp Time
75 301 304 Long Term High Outdoor Temp Value
76 305 308 Long Term High Outdoor Temp Date
77 309 312 Long Term High Outdoor Temp Time
78 313 316 Today's High Barometer Value
79 317 320 Today's High Barometer Time
80 321 324 Yesterday's High Barometer Value
81 325 328 Yesterday's High Barometer Time
82 329 332 Long Term High Barometer Value
83 333 336 Long Term High Barometer Date
84 337 340 Long Term High Barometer Time
85 341 344 Today's High Indoor Temp Value
86 345 348 Today's High Indoor Temp Time
87 349 352 Yesterday's High Indoor Temp Value
88 353 356 Yesterday's High Indoor Temp Time
89 357 360 Long Term High Indoor Temp Value
90 361 364 Long Term High Indoor Temp Date
91 365 368 Long Term High Indoor Temp Time
92 369 372 Today's High Outdoor Humidity Value
93 373 376 Today's High Outdoor Humidity Time
94 377 380 Yesterday's High Outdoor Humidity Value
95 381 384 Yesterday's High Outdoor Humidity Time
96 385 388 Long Term High Outdoor Humidity Value
97 389 392 Long Term High Outdoor Humidity Date
98 393 396 Long Term High Outdoor Humidity Time
99 397 400 Today's High Indoor Humidity Value
100 401 404 Today's High Indoor Humidity Time
101 405 408 Yesterday's High Indoor Humidity Value
102 409 412 Yesterday's High Indoor Humidity Time
103 413 416 Long Term High Indoor Humidity Value
104 417 420 Long Term High Indoor Humidity Date
105 421 424 Long Term High Indoor Humidity Time
106 425 428 Yesterday's Rain Total (0.01")
107 429 432 Long Term Rain Date
108 433 436 Long Term Rain Total (0.01")
109 437 440 Leap Year Date (0-3)
110 441 444 WDCF weatherData (0-255)
111 445 446 Today's High Wind Direction (2 digits)
112 447 448 Yesterday's High Wind Direction (2 digits)
113 449 450 Long Term High Wind Direction (2 digits)
114 451 452 Spare (2 digits)
115 453 456 1 Minute Wind Speed Average (0.1kph)
x 457 Carriage Return